1. Features: exquisite and compact, easy to carry, sturdy and durable, widely applicable, not easy to rust 2. Material: steel 3. Uses: used in aircraft models, remote control helicopters, drones, etc. where the hexagon socket screws need to be removed 4. Weight: about 155g/set (4 pieces/set) 5. Specifications: 1.5/2.0/2.5/30.mm