The Tritium 275 is a liner bag designed to connect to the inside of the torpedo sleeping bags in order to boost the temperature performance by approximately ten degrees Celsius.
It is oriented more towards bivouac use than its lighter-weight counterparts, having armholes to allow freedom of movement whilst sitting. It has a fully insulated hood and a short centre zip. As this was not designed as a stand-alone bag (although it can be used as such), it has not been tested for the EN (European Norm) standards and has no official temperature rating, but we estimate this would be in the range of 5 - 8 degrees Celsius.