Bought one in Singapore for 50-80.00 (can’t remember). Well made, worked with Di2 11spd. Discovered the large bearing is absolute garbage. It has ceramic ball bearings and they very tiny. The bearing doesn’t spin well and feels rough. To top it off the large anodized retention screw is very sensitive. If you tighten it too much the jockey wheel seizes.
Thought maybe it was a crap copy due to the bearing. Disassembled and cleaned everything, no different results. The bearing is just garbage. After a while a friend and I looked up some YT reviews on the actual AB product. Same issues with my budget copy. The bearing for the large jockey wheel is just not freespinning or smooth.
It works like any other OSPW system but there are far better options out there. Token makes a nice budget OSPW. Also look at TriPeak if you can find them.