The Redwood is a "heavy-duty" oversized rectangle bag. The Redwood series use Techloft Insulation. Techloft Insulation consists of multi-hole staple-length micro-denier fibers that have a siliconized finish for maximum insulation, loft, and compactness. The TechLoft insulation will keep you warm and toasty on those colder nights when you'd prefer to have more "wiggle room" than you get with your mummy bag. It uses 2-layer offset construction to eliminate cold spots. For transporting, we include 3 webbing straps with quick-release buckles that keep your "rolled-up bag" secure. Two Redwood -10° bags can be zipped together to create a double bag.• Oversized rectangle