This is very simple. All you have to do is look at your tyre size. The tyre size will be marked on the tyre sidewall. 26"MOUNTAIN BIKE ! Standard hub spacing of 135mm on the rear wheel and 100mm spacing on the front wheel.
26" Mountain Bike Rear Wheel Bolted Screw On with SEALED BEARINGS
8 SPEED 26" MOUNTAIN BIKE REAR WHEEL disc and rim brake including 8 freewheel
HBSSP 26 27.5 29 Inch Mountain Bike Rear Wheelset Aluminum Alloy Rim QR 9mm Wheels Disc Brake 32H Bicycle for 7-12 Speed(Front+Rear wheel,26 INCH)
TINGMIAN 26 27.5 29 Inch Mountain Bike Rear Wheelset Aluminum Alloy Rim QR 9mm Wheels Disc Brake 32H Bicycle for 7-12 Speed(Front+Rear wheel,26 INCH)
QHYRZE 29"/27.5"/26" Mountain Bike Wheelset Front Rear MTB Wheel BOOST Thru Axle 15 * 110mm/12 * 148mm DH/XC/AM Rim 32H Disc Brake 360 Clicks,For 7-12s Cassette(Black rear,27.5'')
26/27.5/29in Mountain Bike Rear Wheel With 1.95'' Tire Quick Release 135mm Hub 160MM Disc Brake Rotor For 7/8/9/10 Speed Rotary Freewheel(7 Speed,26'')