4 Pair 1/2" x 6" Parallel Set Steel Hardened Precision Gauge 4 Pair 1/2'' x 6'' parallel set Accuracy +/- .0003" parallelism in Height ; Made of High Quality Alloy Steel Minimum Height: 1";Maximum Height: 1-3/4";Maximum Thickness: 1/2" Storage case INCLUDED; Case overall dimension: 7-1/4''L x 9-3/4''W x 2-5/8''H Quantity: 1 set (4 pair, total of 8 pieces);Weight: 9.45lbs (roughly)