Here's what other sites are saying:
Western Mountaineering Camp & Hike Bag Expander-Summer BEXSUM. The Expander offers comfort for people who dislike the claustrophobic feeling of a mummy bag (it can be used on the top or underneath your mummy bag.) The Expander is available in either a 3-season or a summer weight. The Expander features a full-length 70 YKK #8 coil separating zipper black 50 denier Ripstop Nylon double layers of Polarguard 3D insulation with offset stitching and built in draft tubes along the zipper. All of these features combine to create a highly compressible expander that is lightweight breathable absorbs little moisture and keeps its loft even when wet.
The Western Mountaineering Bag Expander adds the extra space needed to your favorite Western Mountaineering sleeping bag. Do you have wide shoulders or sleep like a tornado? Never fear! You can now slide into your bag comfortably and roll around as you please with this handy bag expander. It makes the bag just wide enough for more comfort as you sleep. Features of the Western Mountaineering Bag Expander Designed to coordinate with only Western Mountaineering sleeping bags Instantly provides more space in sleeping bag Great for creating extra room for warmer weather camping Also allows you to squeeze into a Western Mountaineering sleeping bag with a snuggle buddy
The Western Mountaineering Sleeping Bag Expander can be added to your favorite Western Mountaineering sleeping bag to create a bit of extra elbow room or breathing room during warmer weather camping tripsThe bag expander is also great for providing just the right amount of space to squeeze into a sleeping bag with that special someone for some world class snuggling Featuresbull Designed to coordinate with only Western Mountaineering sleeping bagsbull Instantly provides more space in sleeping bagbull Great for creating extra room for warmer weather campingbull Also allows you to squeeze into a Western Mountaineering sleeping bag with a snuggle buddy