Eureka Dual 2 Temp 20/40 Degree Tapered Rectangular Sleeping Bag Long Combines the thermal versatility of two temperature ratings with the compact performance of a mummy. 66D polyester ripstop shell with warm-to-touch 75D peached polyester lining. Eureka Rteqmicro insulation, a proprietary blend of micro and macro denier solid and hollow core staple polyester fibers engineered for a soft hand and compressibility yet resilient for durable loft retention. Trapezoidal footbox construction. Full length draft tube and draft collar.