KCM-37-6 1/4” Apex Male Hex Power Drive Universal Extension Adapter have hex tolerances that are on average 48% tighter than DIN and 35% tighter than ANSI requirements. All Apex male hex power drive universal extension adapters have the tightest tolerances for straightness and concentricity in the industry. Quality design and construction give KCM-37-6 1/4” Apex Male Hex Power Drive Universal Extension Adapter a long service life and durability. Apex male hex power drive universal extension adapters are not to be used with impact drivers.