Litepro Carbon Fiber Seat Post with Balanced Double Nail, Ultra Lightweight, Full Carbon Fiber Seat Tube 7075C Seat Bow Clamp Hook, Titanium Alloy Screw 33.9/31.8*580mm specification is only about 300g, ultra-light weight is suitable for mainstream folding car modification and lightening (to make sure the original seat tube diameter is 33.9mm/31.8mm) For Bromp ton Special Carbon Fiber Seat Post Suitable for