Our 1-3/8 inch engine fluid plugs are available in red or black and made of hyper flex polyurethane. Sold individually, these plugs prevent dangerous and costly spills during application. Compared to rubber, hyper flex polyurethane is more compatible with today's fuels and will not swell or deteriorate like the original rubber caps you may be using. Please note that these plugs are for replacement only, and original metal components must be used during application. Choose our engine fluid plugs for a practical and environmentally friendly solution to your engine maintenance needs.