Minoura Mag Riser 3

Every stationary trainer lifts up the rear wheel to enable it to spin the wheel. If you train in this position, you will have to apply unnecessary force to the handlebar to support your upper body. For effective training, it is requemended to use a Mag Riser to raise the front wheel to the same height as the rear.

There are two different grooves on the upper side.
Wide & shallow groove is for MTB's fat tire, and the narrow & deep groove is for 700c road bike tire.