It's light and durable and as almost everyone is running a tubeless system this makes this a great spare tube to stash on the bike or your bag. It's made from Thermoplastic Polyurethane and has a high level of elasticity and durability. Butyl does succumb to cracking and splitting especially when stored on the bike and that's the worst when you go to repair a puncture and you realise that your spare tube is split 1/3 of the way around.
95g for the 27.5" version and 100g for the 29" version. Suitable for tyres 2.2" - 2.6" wide. 42mm valve length with removable core