All 4 mm bits are CNC machined, which is more precision. And the material is CRV Steel, sturdy and durable, which can ensure long time use.

The bit holder has a built-in strong magnet, holds bits securely and transmits magnetism, keeps fasteners firmly in place.

Bit driver handle is ergonomically shaped for maximum comfort while working and particle grip for non slip handling.

Super smooth swivel cap allows you to apply constant pressure while turning and helps reduce hand fatigue.