



Citizen Mechanical Automatic 40mm NH9138-15A
4 interest free payments of $181.75
The Citizen NH9138-15A is a men's open heart automatic dress watch that puts its mechanical movement on show from both sides.
A cut-out in the lower left of the silver dial reveals the balance wheel beating at 21,600 vibrations per hour. Blued hands sweep over the clean face, adding colour and contrast. The 40mm stainless steel case is just 10.7mm thick, slim enough to slide under a shirt cuff. It's topped with scratch-resistant sapphire crystal and fitted with a black leather strap. Turn it over and an exhibition caseback shows the rest of the movement.
Inside is Citizen's in-house Caliber 8229 automatic, a 21-jewel movement that winds itself as you wear it and can also be wound by hand through the crown. It holds about 42 hours of power reserve, enough to see you through a weekend off the wrist.
With 100m water resistance it's tougher than most dress watches. Wear it to the office or a wedding, or anywhere the strap and occasion suit. If you want your first mechanical watch from a Japanese maker that builds its own movements, the open heart design shows exactly what you're paying for.
What we love about this watch: Most automatic watches hide their movement. The NH9138-15A lets you watch the balance wheel beat every time you check the time. The blue hands against the silver dial are a classic dress-watch pairing, and the sapphire crystal and exhibition caseback are rare at this price. It's the watch we'd recommend to anyone ready to step up from quartz.
Orders are dispatched within 1–3 business days from Sydney via Australia Post Express for fast and reliable delivery. Customers located in Sydney may also enjoy the convenience of same‑day Click & Collect, with orders ready for pickup from our Alexandria showroom just one hour after purchase when this option is selected at checkout.
5 Year warranty from Citizen Watches (Australia). StarBuy are Authorised distributors of Citizen Watches. All Citizen Watches are shipped in Citizen original packaging released for Australia. All Citizen warranties are registered online on the Citizen Warranty Portal directly by StarBuy on behalf of the customer. After purchase and shipping by StarBuy, an email is sent by Citizen registering the warranty directly to the buyer. A link to the online instructions manual is also sent within the email. Citizen no longer supply any hard copies of the warranty booklet or the instructions manual.
Specification
Case
- Case Diameter (mm) 40mm
- Case Thickness (mm) 10.7mm
- Lug-to-Lug (mm) 46mm
- Lug Width (mm) 20mm
- Case Material Stainless Steel
- Case Shape Round
- Case Back Type See Through Case Back
- Glass Type Sapphire Crystal
- Water Resistance (m) 100
- Bezel Material Stainless Steel
- Bezel Type Fixed Bezel
Bracelet / Strap
- Material Leather
- Type Strap
- Interchangeable? Yes
- Clasp Pin Clasp
- Clasp Type Tang Clasp
Dial
- Colour Silver
- Finish Smooth Silver Texture
- Indices Type Roman Numerals
Delivery
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How and when will my StarBuy order be shipped?
We ship all orders via Australia Post Express for fast and reliable delivery. We aim to dispatch every order as quickly as possible—typically within 1–3 business days. You'll receive a confirmation email with tracking details as soon as your order ships. -
Can StarBuy guarantee delivery dates?
While Australia Post Express is generally reliable, their delivery dates are estimates only and may vary, especially during busy periods. We appreciate your understanding if your parcel takes a little longer to arrive. -
Will I need to sign for my order?
Yes, a signature is required upon delivery. If no one is home, we recommend using a work address. Australia Post may offer contactless delivery—in those cases, we follow their current safety protocols. Risk and ownership transfer to the recipient upon delivery. -
What if I am not home when my order arrives?
If no one is available to sign, Australia Post will leave a card with details on how to collect your parcel from the closest authorised Australia Post Office. You’ll need to present a photo ID at the post office to pick it up. If you’ve authorised a Safe Drop with Australia Post previously, they’ll follow your existing instructions. -
Will I get a Shipping Notification?
Absolutely! As soon as your order is on its way, you’ll receive an email with tracking details. We kindly ask for your patience—tracking updates may take up to 3 business days after ordering. -
What are your shipping charges?
We offer free shipping Australia-wide with Australia Post Express. For approved brands shipped to New Zealand, a $10 flat fee will be added to your total at checkout. Approved parcels to NZ are shipped within the Australia Post / NZ Post network. -
Click & Collect?
Prefer a quicker pick-up? Our Click & Collect service makes it easy.
Pickup Location:
StarBuy
Suite 23, 112 McEvoy Street
Alexandria NSW 2015Hours:
Monday–Friday: 10am–5pm
Saturday: 9am–12pmHow it works - Your order will be ready for pickup within an hour during business hours (unless otherwise notified). If someone else is collecting on your behalf, just email us their name—they’ll need to show ID at pickup.
FAQ
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Are all items in stock?
StarBuy products for sale on the website are always live and accurate. All items marked ‘In Stock’ are physically in stock with us. Items marked ‘Out of Stock’ are completely sold out. In rare instances where additional items are ordered and the items are being shipped to StarBuy, a specific note will be made on the product page.
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How can I be sure your products are authentic?
We guarantee that all of the products we sell on StarBuy- Are brand new
- Are 100% genuine - manufactured by the named brands, in keeping with their high quality standards.
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Is a tax invoice included with my order?
All orders have an automated invoice emailed to the email address on the order. All items listed on our website are GST inclusive. The invoice clearly shows the GST charged on the purchase as well as our name and ABN number.
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Can an item be reserved or put on hold?
Unfortunately due to the model adopted by StarBuy, we are unable to reserve or put an item on hold. Items on sale are limited in quantity and often sell out quickly.
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Why are StarBuy prices low?
StarBuy is a low cost discount website that buys items in bulk and offers them at the lowest possible prices. We keep our costs low by automating most back office processes to keep our prices world competitive. We ensure that you benefit by buying quality brands at low prices from StarBuy and come back to save money again and again.
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Specifications
- Case Diameter (mm) 40mm
- Case Thickness (mm) 10.7mm
- Lug-to-Lug (mm) 46mm
- Lug Width (mm) 20mm
- Case Material Stainless Steel
- Case Shape Round
- Case Back Type See Through Case Back
- Glass Type Sapphire Crystal
- Water Resistance (m) 100
- Bezel Material Stainless Steel
- Bezel Type Fixed Bezel
- Material Leather
- Type Strap
- Interchangeable? Yes
- Clasp Pin Clasp
- Clasp Type Tang Clasp
- Colour Silver
- Finish Smooth Silver Texture
- Indices Type Roman Numerals
- Type Automatic
- In House? Citizen In House Movement
- Calibre 8229
- Beat Rate (vph) 21600 vph
- Jewels 21
- Movement Hacking? Yes
- Hand Winding? Yes
- Self Winding? Yes
- Power Reserve (days) 1.75 days
- Accuracy -20 to +40 Seconds per Day
- Reference NH9138-15A
- Display Analog
- Gender Male
- Age Group Adults
- Weight (g) 87g (Approximate)
- Shipping Period 1-3 Business Days - Sydney
- Brand Citizen
- Authorised Dealer Yes
- Warranty Period Citizen 5 Year
- Warranty Registration Online by Starbuy
- Warranty Provider Citizen Watches Australia
- Packaging Citizen Official Packaging
- Manual Citizen Online
- Service Centre Citizen - Sydney
Reviews
Need help?
Frequently Asked Questions
What is an open heart watch?
An open heart watch has a window cut into the dial that shows the movement's balance wheel, the part that regulates timekeeping. On the Citizen NH9138-15A, the opening sits in the lower left of the dial, so you can see the mechanism working at 21,600 vibrations per hour. It's a visual signal that the watch is mechanical rather than battery-powered.
Does an automatic watch need a battery?
No. The Caliber 8229 is powered by a self-winding rotor that charges the mainspring as you move your wrist. Fully wound, it runs for about 42 hours off the wrist. If it stops, a few turns of the crown or a few minutes of wear will restart it.
How accurate is an automatic watch compared with quartz?
Mechanical movements are less precise than quartz. The Caliber 8229 is rated between −20 and +40 seconds a day, so most owners adjust the time every week or two. You trade some accuracy for craftsmanship, a sweeping seconds hand and a movement that never needs a battery.
