Sea to Summit Comfort Deluxe S.I. Mat Double Byron Blue

The Comfort Deluxe mats are suitable for car camping or extended basecamp-style trips - you're sure to be the envy of your friends. The Camper Van variant was specially developed for the T5 and T6 California from Volkswagen: The cut-out at the corner allows it to be rolled out precisely. Fits in other vans too, of course.

Delta Core
The Delta Core System maximizes the comfort and thickness of the mattress while minimizing weight and volume. The patent-pending coring process removes 40% of the initial volume of the PU foam, giving the mat a minimal pack weight and size. Importantly, this core technique has the added benefit of leaving the top and bottom of the PU completely intact. This ensures even warmth over the entire length of the mattress and avoids vertical holes or frame-like gaps that have traditionally caused heat to escape downwards. The all-foam surface also offers a significantly improved bond between the foam and the outer fabrics of the mattress, which greatly reduces the risk of delamination. The horizontal Delta Core technology is used in the Comfort Light SI, Comfort Plus SI and Comfort Deluxe SI models.

PillowLock system
The Pillow Lock was developed to keep your pillow exactly where it belongs - on your sleeping mat. Sea to Summit's unique PillowLock velcro closure comes standard with all sleeping mats.

Multi Function S.I. Valve
When packing up, the foam keeps trying to inflate. Sea to Summit has designed the "one-way" inflation valve so that it is reversible and prevents the mat from sucking in air again. This makes it possible to roll out the mat as small as possible without having to fight against re-inflation. Compact and low profile, this valve allows faster inflation than conventional screw-in valves, offers easy fine pressure adjustment and super-fast deflation speed.

R-value
The R-value (resistance value) is a key figure that indicates how effectively the sleeping mat resists heat loss. It also determines how the mat prevents body heat from escaping through cold floor temperatures (which can be much colder than air temperatures). This value can be tested internally, but at Sea to Summit all mats are independently tested in a laboratory to precisely controlled standards. The new industry standard ASTM F3340-18-Tests testing was introduced in 2019 and all Sea to Summit mats released since 2020 will be tested to this standard.