Review on Universal Emblem Bicycle Motorcycles Airtight Tires & Wheels by Guled Probz

They are made of solid aluminum and do not have an internal coating like most aluminum caps. Due to the different metals, it will fuse with your valves! Shouldn't be hard, it's just a bad design decision on your part and it could cost you a lot of money to remove it (may affect the tire pressure sensors inside if removed, if not done that carefully, or if they go all the way into the tires melt metal).