Waterproof ABS plastic parts are durable and smooth. Exquisite workmanship, small and light. Its cool and exquisite appearance gives you a vivid feeling of a real submarine. You can't see if the sub has power or not. When you get the sub, you put it in the water. Its light will come on. Charging is very fast. You can't see if it's charging. Charge as usual. When it comes into contact with water, it starts up normally. It's not broken. Two LED lights on the front, very visible in the dark, let you know where the sub is underwater. There are two rubber drain plugs in case you get water inside the hull. The sub's head has two metal joints to protect it. It gets electricity when it touches water, and loses electricity when it leaves water. It just needs to start in the water. The computer is not plugged in for charging (the plug is easy to burn out the built-in battery). Perfect size for swimming pools, small ponds, fish ponds, rivers and lakes. It can be used as indoor and outdoor toys. Great for outdoor and indoor entertaining. This is the best gift for kids, boys, girls and adults It helps them think together and coordinate their brains and hands. It can exercise children's hand-eye coordination and flexibility.