For Classic Edge models, CleanFire models, & Forge models: Replacement waterjacket snap disc. For E-Classic 1450 (European) models: Replacement waterjacket snap disc for s/n E102167 and up. For E-Classic 2400 (European) models: Replacement waterjacket snap disc for s/n E301509 and up. For E-Classic 3200 (European) models: Replacement waterjacket snap disc for s/n E400306 and up. For Maxim 255 P & Maxim 255 PE models: Replacement waterjacket snap disc for s/n M210003 and up. For Maxim 255 PE models: Replacement transition box snap disc for s/n M210447 and down.