ITEM NAME:100pcs P75-B1 Dia 1.0mm Cusp Spear Spring Loaded Test Probes Pogo Pins tool BX.100 x spring test probes. Needle total length: approx. Spring: Music Wire. Gold Plated. Plunger: Heat Treated Beryllium Copper. Full Stroke: approx. Model: P75-B1. Barrel: Phosphor Bronze.