Wide Stirrup Leathers will use one of these type of replacement Blevins Buckle Slides. Your Leathers may vary in width from 2 3/4" to full 3". Most saddle Makers Cut Stirrup Leathers 2 7/8" to make sure they fit through the Blevins Sleeve easily.
Worn and/or Stretched Stirrup Leathers can measure narrow. Look for cuts or chunks missing, especially on the edges. Consider replacing them if these conditions exist. Also take in to consideration the amount of wear your Stirrup Leathers show and if they appear thin (3/16ths" to 1/8th") Replacement should be considered for safety.
If you have any Questions about the Replacement Slides, feel free to contact me. I'm glad to help get you the right one the first time!