The SB plug bodies have holes in them that allow you to bolt them to a flat surface. I normally use a pair of stainless washers as spacers when I mount them. I usually bolt them up under a gunwale to give them a little cover. You can also get a handle that bolts to the same mounting holes on the non-fixed plug. This makes it much easier to get a good grip without straining the crimped connections. The SB50 size (50 amp) has 2 different size internal pins available as I remember. Off the top of my head, I think that one was good for AWG #10 wire & the other was good for AWG #6. If you buy a complete plug kit with the wrong pins, you can buy replacement pins in the other size for a few bucks.