The SRAM Rival AXS Power Meter Crank Arm comes in two versions: Regular and Wide. The Regular version fits most road bikes, whereas the Wide version uses a longer spindle and is meant for bikes with larger tires such as cyclocross and gravel bikes. If you have a Rival DUB Regular crankset on your bike, you need to order the Regular version power meter and if your Rival DUB crankset is Wide, you must order the Wide version power meter.
In most cases, you can determine which version you have on your bike by your chainrings:
SRAM Rival DUB 1X – Wide
SRAM Rival DUB 2X 43/30 – Wide
SRAM Rival DUB 2X 46/33 – Regular
SRAM Rival DUB 2X 48/35 – Regular
IMPORTANT – If you want to be 100% sure which version you have and leave nothing to chance, you would need to pull the cranks off of your bike and view the writing on the spindle. If you have the Regular version, you will see the words “DUB” printed on the spindle. If you have the Wide version, you should see the words “WIDE” printed on the spindle.