Bitflex bits: the damping zone (only for 25 mm long bits) between the drive and the working tip absorbs excess force peaks that previously led to high wear and destructive ejection forces. The FLEX zone gives the Bitflex a significantly longer service life than conventional standard bits. All bits with 1/4' hexagon drive, length 25 mm, single bits for TX with bore (tamper resistant), without FLEX zone T20 length 90 mm.