This lightweight Exped Waterproof Compression Bag features a trio of horizontal compression straps for optimal load management in narrow internal frame packs or places where small diameter bags fit best. The seams are fully taped and waterproof with all stress points reinforced with extra cross-stitching. Up top is a dry-bag style nylon fold top. Exped specifically recommends it for three-season down sleeping bags like the Exped Woodpecker. Other similarly proportioned sleeping bags fit just fine, too.