Material: Steel alloy
Spring type: Extension
Number of springs: 135
Maximum length: 4.0 inches
Minimum diameter: 3 mm
Minimum length: 0.687 inches

There are sets available that are intended exclusively for compression and sets that are intended exclusively for expansion. Compression only: Compression spring sets with different sizes. Set 1: 320 nibs, 8 each with 40 different sizes. Set 2: 140 nibs, 5 each with 28 different sizes. Set 3: 149 nibs, 5 each with 27 different sizes. Only extension: Tension spring sets with different sizes. Set 1: 200 nibs, 5 each with 40 different sizes. Set 2: 142 nibs, 5 each with 26 and 3 each with 4 different sizes. Set 3: 135 nibs, 5 each with 18 and 3 each with 15 different sizes. Supplied in a plastic compartment box with information on spring sizes and compartment arrangement. Pre-galvanized steel wire.