Sweetskinz Trekking Bike Tire (700c x 37c) Features a graphic retro-reflective design imprinted on the tire surface that reflects light directed on them at nighttime. For example, car headlights or flashlights. The trekking tire features a connected center ridge for a smooth, fast ride and deep groves for gripping loose surfaces, plus the grooves hold the reflective material for the best nighttime visibility