Designed to stop oil from leaking out of the oil cap due to a warped reservoir neck Installs easily into place Slight heating of the reservoir neck with a heat gun may be required for installation Fits Arctic Cat Crossfire, M-Series and Sno Pro '98-'01 Chassis; Polaris Edge, IQ, RMK, SKS, Switchback, Rush, Indy, Fusion, Evolved and Aggressive Chassis; and Ski Doo XS, XM, XP, Rev, ZX, CK, F and S chassis. INSERT OIL RESERVOIR