Replacement leather slobber straps made for 1/2”, 5/8”, and 3/4” poly roper reins. These are size based on Weaver brand reins. Measure the width of the existing strap or rein for size.
 
They are pretty easy to replace, just run the ties thru the existing holes in the poly material, if there’s a little bit of fraying that makes it hard for them to go thru you could try and use a hot nail to smooth the holes out. Small needle nose plyers (like jewelry pliers) can help with grabbing the tie to bring it thru the material.
 
I keep extra good quality 3/4” trigger snaps around which can be purchased with the slobber straps if they also need replacing (the 3/4” will fit the smaller straps to).