1>.Small size 2>.Double-meter ,double-tap 3>.Anti-corrosion 4>.no-pollution 5>.Big ... PUMP seriese were researched successfully by us ,respective for small size double-meter double taps and big power vacuum pump ,main machine ... 5L rotary evaporator and glass reactor.Features:1>.Small size ,rich functions2>.Double-meter,double-tap3>.Main machine is stainless,anti-corrosion ...