I've got a 2016 Novara - Safari, which came with a Shimano - Deore FC-M590 9-speed crankset. I may need to replace the left crank-arm. I came across this one, but it says that it's for a "10-Speed", and that's the way I've also seen it referred to in some documentation from Shimano online. So is there indeed a "different" arm for a 9-speed set, or is this actually the same arm used for both? I'm assuming it's the same arm, but I'd rather get some confirmation on it.

Shimano Deore 10-Speed FC-M590 Left Hand Crank Arm 170MM Black - Y1LD98020