Monroe's Stainless Steel Delrin Knobs are manufactured in a variety of different styles and sizes in an effort to support any application. The main function of Hand Retractable Spring Plungers is to be used in positiners and indexing devices. The standard pins are supplied using stainless steel or carbon steel. Monroe is willing and able to quote any special variations above and beyond the standard offering. However, please be advised that volume restrictions may apply.