The 100mA (0.1A) is a replacement fuse meant to go in your home spa’s PC board. This fuse supplies power to your spa and the rest of its features, so maintaining it is key to the enjoyment of your spa. The slow blow fuse allows more power to flow without overwhelming the circuit.
The 10 Amp Fuse by Master Spas is a replacement part made to go in your home spa’s PC board. The PC board supplies power to the entire spa, so replacing one of its fuses is sometimes a simple fix for issues that arise with your spa or its features.