Hey James, this is a standard US fuse. The UK standard fuses are 6.4mm x 24mm.
USA has 2 standard fuse sizes. Small 5mm x 20mm. Large 6mm x 32mm.
As far as replacement, you can get any cheap fuse of the same amperage value (check the amp rating on the fuse). Of course, you can get better audiophile fuses, but they definitely cost a lot of money.