This is the Modern Fender Style Fuse Holder made by Littelfuse. This fuse holder can be used as a replacement for any Fender Blackface/Silverface Series Amplifier such as the Blackface Princeton Reverb, Blackface Deluxe Reverb, Silverface Twin Reverb, and so on. In the event your original fuse holder cap was lost or damaged, the cap on this fuse holder will fit on your original fuse holder. Easy to install and ready to serve you for the years to come!