Brand: ROCKBROS Product: Shackle Lock Housing Material: Silicone + Aluminum Alloy Lock Head Material: ABS + Zinc Alloy Weight: 564g Battery: 600mAh 3.7V Rechargeable Lithium Battery Smart Unlocking NFC Touch Unlock: Compatible with smartphone/device NFC, keyless 0.3-second unlocking process. Includes NFC sticker for non-NFC capable phones → Universal device coverage. Emergency Unlock Hidden Key Slot (under waterproof cover), functions even during battery failure. Protective Structure Silicone Coating: Absorbs impact energy, reduces wear, prevents 99% of scratches from metal-to-bike contact. Security Construction Aluminum Shackle + Zinc Alloy Lock Core: Resistant to bolt cutters. Sealing & Weather Protection Dust/Rain Protection: Waterproof Type-C port with silicone plug. Fixed Battery Compartment: Prevents water ingress. Energy Management 600mAh Li-ion Battery: 1,500 unlocks per charge. Type-C Fast Charging: Full charge in 2 hours.