Robust and durable, the Royal Marines Limited Edition model mirrors the super tough mantra of the Royal Marines Commandos. Super titanium crafting with shock resistance for extreme toughness. It is also temperature resistant, anti-magnetic and water resistant to 300 metres with full ISO diver certification. This model is limited to 1000 pieces, with each watch individually numbered. Citizen Eco-Drive started with a simple, yet revolutionary concept: a watch that never needs a battery. Citizen Eco-Drive technology harnesses the power of light – from any natural or artificial light source – and converts it into energy which is stored in a permanently rechargeable lithium-ion cell. It recharges continuously in any kind of light to run forever.