Wrench Set Flat Short Box 6 pc N-PowerFit Drive- Increased strength and reduces rounding or fastener damage by distributing stress through a gentle arc in the bore by enlarging the contact surface. Short flat double box ends with proprietary internal hex angle design for improved workability. Solid steel construction designed for maximum strength with minimal wall thickness made possible by tough materials, advanced processing technology, and optimal heat treatement.. Compact external diameter is among smallest in the world and ideal for tight spaces. Contains NM1S-0708, NM1S-0810, NM1S-1012, NM1S-1113, NM1S-1214, NM1S-1417 NTM1S06