West Biking GP-101 Antiskid Super Light Colorful Soft Sponge Foam Bike Bicycle Cycling Handle Handlebar Grip Cover for Road Mountain Bike BMX Folding Bike (A Pair) Sponge, no smell, anti-bacteria, strong wear-ability. Double-opening design easily to install sub-handle. Soft hand-feeling. Absorb shock and vibration. High quality sponge foam rubber handlebar grip. I measured the inside diameter of the grip, it is 17mm / 0.67inches.