Shugaban yana nufin abubuwan da aka yi amfani da su don rufe ƙarshen kwantena don rarraba kafofin watsa labarai na ciki da waje, wanda ake kira ƙarshen rufi. Shirye-shiryen silinda na silinda yawanci suna juyawa. Za a iya raba siffar da rufi surface zuwa convex, conical, flat siffar da kuma hada siffar. convex fuska ne mai nufin waje surface siffar convex fuska, kamar semispherical, elliptical, farantin da uncoupled gefe fuska da dai sauransu. Wasu gas silinda amfani da convex fuska zuwa ciki haɗuwa siffar kasa kai, biyu tabbatar da ƙarfi, kuma iya saduwa da bukatun aminci amfani