3/32x13/16 Piranha. "Soft, Natural, Aromatic Rubber."  Alpha's Piranha tires really bite the track, especially when very clean and/or slippery.   And they feature high quality, lightweight magnesium rims.  These rims give the Piranha tires a big advantage over the other brands using aluminum hubs.  The original Piranhas have won thousands of races!  Features a cup point set screw.  Color: Black only.