HPI high performance air cleaner. HPI .12-.15 size engine hi-performance pre-oiled air filter. (Not for the Nitro Star Pro Engine) HPI high performance air cleaner's main body is made of black plastic. Pre-Oiled Filter Element of Foam (white foam). Base is Centered. INCLUDED: One Plastic Base One Foam Element (3/4" thick, 1 1/8" diameter") Two 10mm Bases (one straight, one angled) Two Nylon Straps.