UTV INC's Yamaha Rhino 660 Siphon Brake is a quick and easy install item that will prevent the engine from building too much pressure and siphoning the oil out into the air box. Installs onto the OEM crankcase breather line before the air box. Will allow crankcase pressure to vent out of the UNI filter and allow oil to enter bottle, and then flow back into the crankcase via gravity. Installs in minutes. This is a MUST have item if you own a Yamaha Rhino 660 model.