What Our Gearhead(R) Experts Are Saying:"The SOL version is my pick for shoulder season. The reflective layer noticeably warms things up without changing the simple, bombproof Z Lite vibe."The Therm-a-Rest Z Lite SOL Sleeping Pad builds on the ultralight classic with a heat-reflective layer that helps hold warmth where we need it most. Same fast fold, same durable foam-just a touch warmer for early- and late-season backpacking, alpine bivies, and high-desert nights.