The MEGAPRO 15 in 1 ShaftLOK Screwdriver outperforms the best screwdriver set when it comes to it’s compact yet versatile application. The locking shaft eliminates the danger of bits falling out of the shaft when getting partially “stuck” in the fastener. The 6″ Locking Extensions lock into the ShaftLOK screwdriver shaft providing a slim profile into those hard to reach places. 0.375″ (9.6mm) min. clearance. Link multiple extensions together for extra long reach.