42RE/42RH/46RE/46RH/47RE/47RH/48RE, And A727, A904 Transmission Sonnax Replacement Seal Kit Sonnax replacement seal kit 28841-04SK includes all the necessary seals to refurbish the piston in Sonnax accumulator piston kit 28841-04K for listed Chrysler units. The PTFE seals prevent piston to bore contact and the rubber D-rings vastly improve sealing compared to aftermarket steel rings. Contents Scarf-Cut Seal PTFE, Large Scarf-Cut Seal PTFE, Small D-Ring Rubber, Large D-Ring Rubber, Small