Just a heads up if you have an older set of spare Alpha scratchers. AC narrowed the scratcher coil and bushing on the 858s. In the photo - left is the old style from a 19 Alpha and the right is the 858. The 858 bushing is too short for the older style scratcher. I made reversible scratchers out of the spare set I had laying around for my 19 Alpha; had to order the older/longer bushing so I can install them on the 858. I run this style of reversible scratcher on my twin rail ascender and they work great. I’m hoping they will work just as well on the 858.