The 17-Piece 1/2 in. Drive Flexible Ratchet with GO Through Sockets toolset includes 1/2 in. drive. Each drive comes with the Ratchet, extension bar and 1/2 in. adapter. Sockets are designed with Go-Thru mechanism to replace 1 standard and 1 deep socket. it eliminates the need for deep sockets. 17-Pieces 1/2 in. Drive with Flexible Ratchet and Go Through Sockets. GO Through Sockets allows access where deep sockets cant be used. Multi-use for home or automobile. Includes heavy-duty case for easy organization. Package Includes: 1-piece Flexible Ratchet off Beam 75-Box End GO-Through Wrench1-piece 20 mm x 1/4 in. DR. Socket Adapter 1-piece 20 mm x 3/8 in. DR. Socket Adapter 1-piece 20 mm x 1/2 in. DR. Socket Adapter 1-piece 20 mm x 75 mm L GO-Through Extension bar 12-pieces GO Through Socket (mm size): 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm and 19 mm.