Mansfield Dual Flush Valve Tower - 308DF3 Mansfield Dual Flush Valve Tower - 308DF3 Provides a 1.1 and 1.6 gallon flush. Fits Mansfield Summit tank model 3386. 13-1/2" overall height, 12" from top of valve to toilet tank. Includes flapper, chain, stainless steel clip, seal, spud gasket, and nut