ITEM NAME:100PCS P75-B1 Dia 1.02mm 100g Cusp Spear Spring Loaded Test Probes Pogo Pins V3.50 x spring test probes. Spring Pressure: 100g. Needle total length: approx. Spring: Music Wire. Gold Plated. Full Stroke: approx. Barrel: Phosphor Bronze. Plunger: Heat Treated Beryllium Copper.