Hello, The Fuse Lamps are specified as: AC Fuse #81 lamp 6.5 Volt 1.02 Amp Bias Fuse #49 lamp 2 Volt, .06 Amp Neon short lamp NE-45/B7A or NE-51/B1A depending on model. A search for TV-7 Tube tester, Tube Tester, Hickok, Etc Will yield more information. Also there are a couple of sellers of the lamp sets on E-Bay, just find the one that is most reasonable. Some auto parts stores might still have the #-81 lamps but they have been out of production by the usual USA Mfg's for awhile now with little use other than vintage 6 volt vehicles or these tube testers. It's a great tester! Enjoy Bill KB3DKS/1
