Knob, Metal, W/Pointer, 2-1/2" Od Dia., 1/4" D-Stem, Flat Down, W/Set Screw., Fits Apw Wyott Models~, Gcb-18H, Gcb-24H, Gcb-36H, Gcb-48H, Gcrb-18H, Gcrb-24H, Gcrb-36H, Gcrb-48H, Ggm-18H, Ggm-24H, Ggm-36H, Ggm-48H, Ghp-2H, Ghp-4H, Ghp-6H, Ghps-2H, Ghps-4H, Ghps-6H, Ghpw-2H, Gww, Hr-20, Hrs-20, Hrs20,