The compound that Continental have used for the Sport Contact uses a mix of carbon and silica as the main agents. Carbon aids tread life whilst the silica boosts grip levels. The tread uses a high concentration of natural rubber, giving superior wet grip to synthetic compounds. Includes moderate grooves in the tread to guide water away from the contact area for your safety on wet roads. The compound that Continental have used for the Sport Contact uses a mix of carbon and silica as the main agents. Carbon aids tread life whilst the silica boosts grip levels. The tread uses a high concentration of natural rubber, giving superior wet grip to synthetic compounds. Includes moderate grooves in the tread to guide water away from the contact area for your safety on wet roads. Safety system puncture resistance. Black with reflective strip on sidewall 28 - 406 20 x 1 1/8