This is a replacement master cylinder for a Model 6 disc brake surge coupler with springs and brackets manufactured by Dexter Marine / Titan / Dico. Fits Dexter Marine / Titan / Dico model 6 surge brake couplers. This master cylinder is designed to work with disc brakes. Its an easy bolt on installation for replacing your old worn out / blown seals master cylinder. Comes with everything pictured: the master cylinder, boot, lid, gasket, bolts,springs,spring bracket and cap. Dexter Marine / Titan part number 1777405