The Orangatang In Heat wheel is 75mm diameter with a contact patch of 56mm. They come in three durometers: orange are 80a, purple is 83a and yellow is 86a The In Heat features an offset design, with hard sharp edges for grip, thick lips for maintaining speed, and rippled inner walls for progressive energy return.
Check out this Youtube video to see the Orangtang Inheat wheels
in action .