No. 140550 includes T10, T15, T20, T25, T27 and T30. No. 140551 Metric set includes 4, 5, 6, 7, 8, 10mm. No. 140552 includes SAE: 1/8, 5/32, 3/16, 7/32, 1/4, 5/16, 3/8". No. 140553 includes Metric: 4, 5, 6, 7, 8, 10mm; SAE: 1/8, 5/32, 3/16, 7/32, 1/4, 5/16, 3/8".