The Ko-ken SKU 4277 is a 27-piece 1/2" Sq. Dr. 12-point metric socket set. It includes 4405M 12-point sockets in sizes 10mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 21mm, 22mm, and 24mm, and 4305M 12-point deep sockets in the same sizes. The set also features a reversible ratchet with a knurled handle (SKU 4750N), a 125mm extension bar (SKU 4760-125), and a 380mm breaker bar (SKU 4768N-380). All components are neatly organized in a metal case with a blow-molded insert for efficient storage and easy transport.