Exped's Large Schnozzel Pump Bag allows you to inflate your mat using muscle power rather than lung power - much easier.
Exped says:
Pump and waterproof compression bag in one. This extra durable Schnozzel Pumpbag allows swift inflation of Exped mats in 1-2 compressions. For older mats with 30 mm instead of 20 mm valves use FlatValve adapter.
Exped's Schnozzel pump bag, is ideal for larger sized mats and double mats. Its remarkably easy to use you attach it, with a bit of wafting it inflates with air - then you compress it forcing the air into your mat. Infinitely better than using your lungs.
Because of the valve arrangement it can only be used with Exped mats.