Only the Assioma power meter can read the oval chainring correctly due to how they measure the power. Most power meters, (even Garmin pedals) from what I’m reading, use the average power of a circular chainring. (sorta, I’ve read somewhere). If you use a chainring power meter/spider type like P2MAX, you have to get the silver version of AbsoluteBlack. Otherwise, it won’t work. If you want the AbsolueBlack subcompact (46/30, 48/34), it won’t work if you have a spider-type PM like P2MAX, SRM, QUARK, etc. I use 34 oval from AbsoluteBlack on my P2Max NG eco. And install 46/30 on my Shimano Ultegra crank with Assioma Power meter on my climbing bike. So far I like riding AbsoluteBlack.