Exped says:Pump and waterproof compression bag in one. This large, extra durable Schnozzel Pumpbag allows swift inflation of Exped mats in 1-2 compressions. It has a volume of 85 liters (5187 cu in). For older mats with 30 mm instead of 20 mm valves use FlatValve adapter.(Again, it can double as a waterproof stuffsack too!)