Screwdrivers feature a hexagonally shaped head to prevent them from rolling. When not in use, the blade can be reversed into the screwdriver body for conveniently and safely carrying them in pockets. Size takes no more room than a penknife. Overall length with blade: No. 553A, 4 Y" (110 mm); No. 553B, 5 5/8" (140 mm). Same blades as 559 above.