Material: Each set includes 3 high quality cross-shaped zinc alloy keys, using electroplating process, never rust, durable, can be used for a long time. Anyone who works with control cabinets needs this. There are 4 ammeter key shapes, 2 square, 1 triangle and 1 key shape as shown in the picture. They have functions complete and can be used depending on size and shape. Suitable for air conditioners, electric vehicles, cars, elevators, etc. Size: as the pictures show, suitable for you to carry or put in your bag. It There is a hole in the middle of the key, which can be hung on the key ring for easy carrying. Wide range of uses: the multi-function key can be used as a practical key and turning screw, suitable to many electric valves, water, gas, trains, cabinets, elevators, etc.