1.Special heat treatment for the best combination of strength and impact resistance. 2.Advantages: Factory direct price ( ... /4" & 3/8" & 1/2" Dr Socket and Wrench Combination Wrench Set SPECIFICATION DETAILS:10PCS-1/4" DR. METRIC SOCKETS : 4,5 ... ,2,2.5,3,4,5,6,7,8,10MM12PCS-SPANNER: 8,9,10,11,12,13,14,15,16,17 ... ,18,19MM3PCS-OFFSET RING SPANNER: 8-10,12-13,17-197PCS-BITS: T10,T15,T20 ...