US sizes. 8-piece set. Incl. 8 wrenches with an open end on one side and a ratcheting box end on the other side; with identical sizes on both ends. Packed in a robust textile pouch with hook and loop on the rear side. Color coded for size. When everything fails; it''s time to play your Joker. - Open end. The Joker has a non-angled 12-point beak; therefore it requires just 30° of working space; otherwise it functions just like a regular open end wrench. The dark metal plate dual functions as a retainer; preventing the nut to slip through the wrench beak or it holds the nut. 30° further the metal retainer plate allows the nut to slide through; or grip it since the metal plate is equipped with a hardened ragged edge. The teeth of this edge will ''bite'' itself into a rounded-off nut; loosening it where others do nothing but slip-off. - Box end. The box end head is angled at 15° from the handle. Comes with a switch for ratcheting direction and a very fine 80 tooth ratchet for a small 4.5° return angle. Set includes. Size: 5/16" Overall length: 144mm. Size: 3/8" Overall length: 159mm. Size: 7/16" Overall length: 165mm. Size: 1/2" Overall length: 177mm. Size: 9/16" Overall length: 188mm. Size: 5/8" Overall length: 212mm. Size: 11/16" Overall length: 235mm. Size: 3/4" Overall length: 246mm.