Limited edition of88 piecesr u boat watch chimera 43 pvd black diamonds limited edition u boat chimera 43 pvd black diamonds is innovative steel crown release system patented at 8 oclock for easy time and date settingr automatic mechanical movement modified and personalized to u boat specifications for stem position at 9 oclock height 4 60 mm 25 jewels power reserve 38 hours frequency 28800 vibrations per hour 4 hzr strap is hand made and hand finished alligator black decor