ITEM NAME:Index Plunger With Ring Pull Spring Loaded Lock Pin M6-3 Stainless Steel img *{margin:0;padding:0;.Ring pull plunger. Also known as spring loaded pins, retractable plunger pins or index pins. 1 x Index Plunger. Size: M6, M8, M10, M12, M16. Zinc plated steel/stainless steel pin. These hand retractable components are suitable for a wide range of applications.