New Style High Pressure Sealing Head Assembly for .88" (7/8") plunger units, 55,000/60,000 psi. Used on all SL-V, E-Series and S-Series units with 15hp - 60hp pump motors, plus the 100D (100hp Dual). Must be used with new, shorter liner sleeve (see kit C0146 which is this sealing head PLUS the new sleeve). Going forward: C0123 is just the Sealing Head Body; K0197 is the Seal Head Repair Kit.