The insert's lateral grooves flex vertically, absorbing big impacts while retaining lateral stability and durability, providing a more predictable handling car. A laterally stable, vertically compliant insert combined with a stiff wheel results in faster lap times. FeaturesReduces tyre expansion & increases stability. Prevents the tyre from collapsing. Improves overall vehicle handling. Provides consistent tyre performance. Included itemsDescription. QTY. Blue 1/8 Buggy & 1/10 Short Course Grooved Foam Inserts. 2.