●Bicycle seat post O-ring strong elasticity and high compatibility. Fit for seat post diameter 25-30mm ●The bicycle seat post cover can protect the seat colour and keep the seat tubes clean and prevent the ingress of rain, cement and sand. ●Made of silicone material, highly elastic, durable and non-slip. ●The waterproof cover of the seat post is good decorative for bicycles, adopts bright colours and a beautiful appearance for your bike.