Sold as two bushings and a sticker.
APS stands for Animated Polymer System. This urethane is very lively giving you more turn that a same durometer stock bushing, with lots of rebound. APS doesn’t compress the same as stock bushings and other formulations, so you can take it from the standard just snug washers to a few full turns without effecting the compression and decompression characteristics.
Tall Barrels are just taller barrels than a standard barrel. These are made for reverse kingpin trucks that use tall bushings, and have a 2.75" kingpin.
For most downhill and free ride applications the double barrel set up gives you a nice supportive Break from Center, and a good return to center feel as well.