Swivels at least three of them, on those beaver traps. If they twist and it doesnt give or the swivel hangs up they will wring out. No matter what type of lams you have the only way to prevent wring outs is to swivel the tar out of the traps. And make sure the drowner is clear of debris. You want them to go down the drowner fast and no hang ups. If land setting for them again swivels and more swivels. You want that trap to swivel with the beaver. They will roll like crazy when caught on ground.
willie main thing when setting up yer drowner is make sure theres nothing with in reach of the beaver in the trap. No under water snags it can get the trap hung up on to keep the swivels from working like they should. I set for back foot 99% a the time never had a ring out on back foot catch ever.