Movement - Japanese automatic movement (Seiko NH35) Movement - Power Reserve 36-41 Hours Movement Variance - -10/+20 seconds per day Case Material - 316L Stainless Steel Case Diameter - 44mm Crystal - Anti Glare, Scratch-Resistant Sapphire Crystal Bezel - Uni-directional rotating bezel with 120 clicks Crown - Screw down crown Water Resistance - 20 ATM Lume - Hour/minute hands and hour markers. Lume is expected to last for 30minutes with exposure to light for 1 hour Function - Time and Date Strap - 22mm width. Silicon strap with self release spring bar (no tools required to change strap)