Small Hole Gauge Set, Range 0.125 in to 0.5 in, Contact Style Split Ball, Maximum Measurement - Inch 0.5 in, Maximum Measurement - mm 127 mm, Minimum Measurement - Inch 0.125 in, Minimum Measurement - mm 3.18 mm, Number of Pieces 4, Overall Length 2 63/64 in; 3 7/64 in; 3 15/32 in; 3 37/64 in, Locking Style Knurled Nut, Maximum Measuring Depth 5 in