Rotary encoder holder + wheel

For a rotary encoder (i bought this one: http://www.pieterfloris.nl/shop/product.php?id_product=572) i've made a holder that keeps it into place, makes sure the rotary encoder itself can not move and still enables the wheel to rotary easily.
The wheel is also custom made, and fits perfectly on the rotating part of the encoder, since it's got a flat side to it. The piece of rubber i rapped around the wheel comes from a very cheap mouse from a brand called sweex