Custom Silver RO Style Skeleton Mod Watch Sapphire Crystal w/Nh70 Automatic by Grail Mods. NH70 Automatic Movement: Up to 41 hours power reserve. This Seiko mod watch comes with no logo and no logo will be installed. At Grail Mods, we hold ourselves accountable to the highest standards in craftsmanship. All of our watches are meticulously tested, including pressure testing.