A connection of first and second members wherein each has a body and a connecting end with an inner surface so the second connecting end has an outer surface shaped for telescoping into the inner surface of the first connecting end. A shoulder is located on the second member and a groove is in the outer surface of the second connecting end. A raised nub on the inner surface of the first connecting end is radially inward to engage the groove. An elastomeric gasket is positioned to bear against the shoulder and be compressed between the first and second bodies. An engaging trough in the groove holds the first connecting end against the shoulder with the nub against the groove by the compression force of the gasket. An indexing trough in the groove positioned along the groove beyond the engaging trough allows the nub to follow therethrough and slightly compress the gasket thus giving the user a tactile indication that it has been rotated beyond the engaging trough. A method for fluid tight attachment of members of a medical device has steps including providing the connection of the first and second members with ends by telescoping the ends. Locating a groove for operating the groove as a cam and locating a raised nub of material on the inner surface of the first connecting end for positioning the raised nub to engage the groove for operating the raised nub as a follower of the cam are steps. Compressing a gasket seal between the first connecting end and the shoulder while making the gasket seal from an elastomeric material is a step. Positioning an engaging trough in the groove to hold the first and second connecting ends against each other is a step. Positioning an indexing trough in the groove so when the nub is rotatably forced past the engaging trough it will further compress the first end against the gasket is a step.