SKX007 Case Backs for Seiko Mod Builds
Find replacement case backs for SKX007 Seiko mod builds from 20 options at Watch&Style. The collection covers sapphire (clear) case backs that let you display the NH35/NH36 movement (9 options) and sterile (solid) case backs that keep the build closed and minimalist (11 options) — available in both Slim and Thick profiles to suit your case stacking preferences. Whether you're showing off a decorated NH movement, switching from a stock SKX007 case back to a modded look, or matching the case back finish to your case build, this is where you find the case back that closes out your build.
Sapphire vs. Sterile Case Backs
Sapphire case backs feature a clear sapphire crystal window that lets you see the NH35 or NH36 movement working underneath — popular for builds that want to display the rotor, jewels, and balance wheel. Sterile case backs are solid metal with no window and no engraving — the cleanest, most minimal closure for builds that prioritize a low-key look. Both types are CNC-machined from 316L stainless steel and tested to water-resistance standards appropriate for daily wear.
Slim vs. Thick Profile Options
The collection offers two case back profiles. Slim profile case backs (11 options) reduce overall case thickness when paired with a slim sapphire crystal — useful for bringing an SKX007 build closer to a dress-watch wearing profile. Thick profile case backs (9 options) maintain the standard SKX007 case back depth — the safer choice for builds that want stock-equivalent water resistance and case feel. Match your case back profile to your overall case stack: slim case + slim crystal + slim case back for the thinnest possible build, or thick variants for a more traditional SKX007 wearing profile.
Finishes & Style References
Finish options span polished steel (7 options, the dominant choice), brushed steel, sandblasted black, matte black, gold (4 options), rose gold (4 options), and Chameleon (color-shifting) variants — so the case back finish can match (or deliberately contrast) the case finish on your build. Most case backs in this collection are sized for the standard SKX007 case family (which also fits SKX009 and SXK011/0200 cases), and most aftermarket SKX007 conversion cases on the site are designed to accept the same case back dimensions.
Fitment & Movement Compatibility
Case backs in this collection are sized for SKX007, SKX009, SXK011, and most SKX007 replacement and conversion cases — confirm the case back compatibility note on your specific case product page before ordering. The case backs are designed for the NH35 and NH36 movement footprint with the standard gray spacer (note: some case backs require the specific spacer included with your movement; check the product description for spacer compatibility). Pair your case back with matching SKX007 cases, crystals, bezels, dials, and bracelets from adjacent collections to complete your build.
Frequently Asked Questions
What's the difference between a sapphire case back and a sterile case back?
A sapphire case back has a clear sapphire crystal window in the center, letting you see the movement underneath — popular for builds that want to display the NH35/NH36 rotor and jewels. A sterile case back is solid metal with no window — the cleanest, most minimal closure with no engraving or visual interruption. Both are 316L stainless steel; the choice is purely aesthetic.
Will these case backs fit my SKX007 conversion case?
Most SKX007 conversion cases on Watch&Style are designed to accept the same case back dimensions as the original SKX007 — but always confirm by checking your specific case product page for case back compatibility before ordering. Some specialty conversion cases (like certain Tuna or Square conversions) may use different case back sizes.
Should I choose a slim or thick profile case back?
Slim case backs are thinner than the standard SKX007 case back, reducing overall case thickness when paired with a slim sapphire crystal. This brings an SKX007 build closer to a dress-watch thickness for builds that want a less bulky wearing profile. Thick case backs maintain the standard SKX007 depth — the safer choice if you want stock-equivalent feel and don't mind the additional thickness. Check the product description for the specific water-resistance rating on each case back.
Browse the full case back collection above to find the case back that closes out your next Seiko mod build.