Edit inner foams are colour-coded and graded for hardness.

The Soft black foam measures at 35 degrees, and our Medium purple foam is 55 degrees, as measure on a calibrated durometer. 

Foam Insert for 1/8th Tyres (Soft - Black) (Pair)
Ideal for use inside the following tyres:
Schumacher / Ballistic Buggy. Minispike and Minipin. Compound (Green). On greasy/damp tracks

Foam Insert for 1/8th Tyres (Medium - Purple) (Pair)
Ideal for use inside the following tyres:
Schumacher / Ballistic Buggy. Minispike and Minipin. Compound (Yellow) On high grip grass and Astro Turf Tracks