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 1.5 inch standard pump union is a universal pump union used for complete assembly of your replacement pump. Should fit any 1.5 inch end on most pumps.