The Round Rock Solid Pack by Granite Gear. A Granite Gear Classic. We designed these stuff sacks to easily compress lofty Items such as sleeping bags and clothing to a nearly rock solid state. The unique design evenly distributes the stress of compression and prevents bulging. The original-often copied but never equalled. Accept no imitations!. Features of the Granite Gear Round Rock Solid Compressor Compress your lofty Items to a rock hard state without bulging.