Do it yourself installation instructions on back Annual replacement recommended Kit includes: M50597 Nozzle Original equipment replacment part fits the heaters listed below: FREE SHIPPING!! REDDY: R50, R50A, R50B DESA: C50D, C50E, C50F MASTER: B50D, B50E, B50F KNIPCO: F50E, F50F, F50G REMINGTON: REM50, REM50W, REM50A,