HPG Panel-Mount Fuse Holders Eaton HPG Panel-Mount Fuse Holders provide supplementary protection of transformers, relays, ballasts, and small motors. These fuse holders feature a bayonet-type knob with a UL94HB-knob rating. The HPG panel mount fuse holders include 12.7mm (½″) mount knock-outs with locknut. These panel mount fuse holders offer a 600V voltage rating.