Vibrato LDR for Fender Vibrato and Tremolo. Primarily used by Fender® in numerous models like Deluxe Reverb, Vibrolux Reverb, Super Reverb, Bandmaster Reverb, Twin Reverb. Blackface and Silverface ! if the Tremolo/Vibrato loses its depth or completely stops to modulate, a bad LDR is mostly the reason. The photo cell is aging and after 20-30 years it might lose its function partly or completely. This part is for repairing of historic amplifiers.