As part of their Ultralight series this summer, Therm-a-Rest® introduces the new ProLite™ Apex™ Mattress. With the best warmth-to-weight ratio in the self-inflating category, the ProLite Apex weighs in at an ultralight 630g, and is ideal for lightweigth backpackers this season.

The mat features Therm-a-Rest's StrataCore™ Construction, a continuous layer of thermal foam nestled between alternating ridges of air designed to trap warmth. The expanding foam core self-inflates, and can be topped off with just a few breaths for personalised firmness. Tested in both the lab and the field, this innovative foam construction delivers added comfort and stability, without the excess weight.

At 5cm thick, and with an R-Value of 4.0, the Apex is Therm-a-Rest's warmest ProLite to date, and is ideal for all-year round adventures. Packing down small, the mat easily fits into your pack, and is perfect for fast and light adventures, where reducing weight is key.

Regular: 630g, £125.00; Regular/Wide: 790g, £135.00; Large: 850g, £145.00

The ProLite Apex is available in stores now.