ORK1228 is the maintenance kit for Morita WS-12 air/water syringe adapter. This maintenance kit will replace internal O-Rings for the Morita WS-12 conversion kit. With continued daily use of adapters, replacing O-Rings every 6 to 12 months ensures no leaks or issues with adapters. If you are unsure, please visit our SYRINGE ID for further assistance.