Whats a swim jig?
If I am throwing the original its a 5" grub 40% the time, Paca Craw 40%, and a boot type trailer like the Keitech, grass pig, or whatever floats your boat the rest of the time.
A break down of when and why I throw a different trailer in the mix, in the spring as the water is warming I throw the grub, it is a smaller profile more of a finesse type trailer, once the fish go post spawn and can be shallow deep whatever I turn to the action craw type trailer, it allows more versatility, swim it, jig it, dead stick it, in my mind it looks good doing all of them and that's what matters to me. Moving into late summer/ fall bass in my area are often feeding up chasing bait fish and that's when I switch to the boot tail trailer, I can change the trailer to change the look, there is a lot of versatility in these types of trailers.
If I am throwing a swim jig like the flip and swim
The trailer could be anything from a Action claw type trailer like the Paca to a creature style bait, the Missile D-bomb is my latest and greatest when adding a bulky trailer, to bigger paddle tail type trailers, the subwoofer is a good choice here also. It depends on what I am doing as to what trailer I am using, flipping, fishing isolated cover, or deep water swimming.