[Boatanchors] OT: I need a 15 amp pigtail fuse for 300 watt tube bass amp

[Bob Young]

I use 300 watt all tube amps to play bass through and they have an external 10 amp fuse in series with a soldered in 15 amp gjv fuse (pigtail fuse), does anyone know a source for these, are they fast blow? This fuse blew before the ten amp slow blow did. There is an ad on ebay for 15 amp ceramic pigtail fuses:                                                                        http://www.ebay.com/itm/390562153985?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

But I'm not sure they are correct ones and the sellers know nothing about them, any help will be appreciated, I got to get this thing working pretty soon,

Bob 
KB1OKL