Are they any good?

Are you talking about swivels like mb crunch proof with 2 j hooks.

PIT center locators? If so I have a few Vic/Monty’s rigged up with them. No complaints. Held yotes fine.

Is this what you are talking about.

Center locator that is crimped to trap. What yoteguts is referring to.

That won't strengthen the base plate, and helps position the animal's foot in the top center of the jaws where it's easiest to pull out. Keep the trap side swiveled so their foot goes to the tightest part of the trap. It's also easier on your knee when setting traps. $.02

Yes, I'm talking about pit center locators

They work and keep your trap light if you like a lighter trap.

I think those will work just as good as any thing else, you could weld them on also. If you want to add strength to the trap use a full length base plate and weld them on.

No need to weld them. I've gotten traps with them on them and they hard to pry off even with good tools. No animal is going to open them up, something else will give first.

I use on #5 Bridger longs and they work great.

Have used them for 20 years with no welding (but i use a different swivel) on my (old 1982) round jaw MONTGOMERY #2'S. Not 1 problem of bending (or losing a critter due to center swivel) in all that time. Liked them so much i added them to my (old 1981) 1.5 MONTGOMERY RJ's. This was before all the New Trap styles came out so their new designs may be better but the critters tell me when to change and so far I can't see any reason too (unless you occasionally like a bigger, cast jaw trap like me)........................ the mike

Same

Looks like it may be fine for coyote. Not in mountain lion country.