aM slow blow cartridge fuse. 20A. 38mm long x 10.3mm diameter.
These fuses differ in size to the more universal 'SC' (SLC. SEC, etc) series cartridge fuses.
All fuses are tested prior to dispatch Fuses carry no warranty due to their consumable nature - these fuses have been tested for continuity and are operable.
Do not replace a blown fuse without first determining the reason for failure as the replacement of the fuse may result in subsequent fuse failure a second time.
Fuses fail through long term stress, low voltage/high current fluctuations, and from equipment failure. Repeated fuse failure may require testing of incoming power supply voltages if spa equipment has tested OK.