Magnetic bit holders with universal 1/4 hex shank has built-in strong magnetism to better stabilize the drill bit, and will not drop the drill bit. The quick release design makes your life and work more efficient, in one step, convenient and fast.The location of the magnetic force:The connection between the extension rod and the bit. (The magnetic force cannot be transmitted, and the bit head cannot be made magnetic ) Bit extension for impact driver is made of stable and strong chrome vanadium steel with excellent concentricity. The beautiful red coating can provide secondary protection to the metal, which is more durable and more protective. In order to meet the needs of various environments, this bit holder tool kit combines three different lengths, namely: 2 inch/60mm, 4 inch/100mm, 6 inch/150mm. The three lengths are highly versatile and easy to replace. Drill bit extender suitable for pneumatic screwdriver, electric screwdriver, pneumatic drill, manual screwdriver and all 1/4-Inch drive bits tool. It is very suitable for working in some places that need to extend the head. Whether it is life or work, there will always be some narrow or difficult to operate environments. At this time, you can only use 3 lengths of magnetic extension drill rods to provide you with efficient and convenient Service. The package contains: 2 inch, 4 inch and 6 inch quick release magnetic drill bit holder with 1/4 hex shank.