Aldeco 9 -Piece Allen keys are available in various sizes, with the most common sizes ranging from small enough to fit tiny screws in electronics to large ones used in automotive and industrial applications. They are commonly made of hardened steel to withstand the torque applied during use.The design of the 9-Piece Allen key allows for a snug fit within the socket, reducing the likelihood of slippage and minimizing the risk of damaging the fastener or the surrounding material. This makes it particularly useful in situations where space is limited or where precision tightening is required.