NMK920 Tuna SKX007/SRPD Watch Case Bundle: Black and Gold Finish


Get 20% off any bezel with the purchase of a watch case! Use discount code BEZELBUNDLE during checkout.

Aptly named for its resemblance to a can of tuna, the NMK920 Tuna SKX007/SRPD Watch Case Bundle: Black and Gold Finish is our take on one of the most original and iconic (some would say extreme) dive watch designs released by Seiko. Now you can cook up your own Tuna in any style you like.

Not just a pretty face, the Tuna was (and still is!) an engineering marvel designed to solve issues professional divers faced at extreme depths, producing many industry firsts - it's iconic shroud, vented straps and L-gaskets just being a few. If you want to learn more about about the history, design and legacy of the Tuna, we did an excellent Dive Deep article that you can find here.

Case Specifications:
Diameter: 44mm
Lug to Lug: 46.5mm
Thickness: 11.3mm (without caseback)
Lug Width: 22mm

- Case Bundle includes Bezel and Crown
- 316L Surgical Grade Stainless Steel Construction
- Fits all original and aftermarket SKX007/SRPD mod parts (except bracelet)
- Water Resistance as OEM

Each case comes in a set inclusive of:
- 2 x 22mm Spring Bars
- 1 x Bezel Click Spring
- 1 x Crystal Gasket
- 1 x Caseback Gasket

Customer Reviews

Based on 21 reviews
Chris C. (San Diego, US)
Great quality case for a tuna conversion

I looked at other options but the big thing that I noticed on an original tuna and this case is how seamless the shroud fits with the case on the underside. There are no gaps between the case and the shroud. I had to watch a lot of videos and look at pics of other tuna conversion cases to see that all the others are just a shroud on a basic case. The gaps underneath can be unsightly and I would think uncomfortable. The Namoki tuna case looks amazing! It’s a heavy piece but well built. I was concerned that I couldn’t chose my own crown and bezel but the combo is really beautiful. Looking forward to an awesome build!

DEH (Hareid, NO)

This case is high quality and easy to wear on the wrist! Not too big and not too small. Very happy with the new tuna mod! Looking forward to shop more modparts from Namoki again!

DEH (Oslo, NO)

Easy swap for my SRPD59K1! The case is high quality and the top hat crystal is just perfect for the case and bezel

Dan V. (Portland, US)
First (and not last) custom build: Orange 5KX Tuna

I’ve always hired other modders to make my custom Seiko builds, but I decided I’d try my own. Namoki made this SKX/SRPD tuna case kit, which was truly “plug and play”. I transformed my beaten up SRPD59 and dropped the dial, movement, handset, and chapter ring into the case. Everything fit perfectly. The Namoki double dome sapphire was perfect was a perfect fit too. The included caseback and crystal gaskets were a nice touch. An overall easy and fun experience. I’ll be back to make myself a custom SRPD Emperor Tuna.

Kirk S. (Edmonton, CA)
Tuna case build, redux

Dial and hands update. Still an amazing case, thanks Namoki!