1、Applicable Models: RV toilet flush seal is replacement for Dometic 300 310 320. Please confirm whether your model is applicable before buying. 2、OE Number: The part number of RV toilet seal kit is 385311658, please confirm whether it is consistent with the OE you need. 3、Superior Material: Flush ball seal gasket is made of high class material, which is sturdy and durable and has strong sealing and long service life. Easy to solve the problem of water leakage. 4、Perfect Fit: Comply with OEM specifications to ensure that the shape and function match the original vehicle, perfect replacement without additional modifications are required. 5、Easy to Install: Turn off the water supply, remove the old flush ball, and place the new flush ball back in place. Once installed, check for leaks. Remember to place the flush ball with the marked side up!