Our liners don’t have zippers* – you slide into them through the opening at the top (in the case of the Adaptor and Reactor series, the drawcord channel is a contrasting color which makes this even easier).
There are several reasons for not adding a zipper to a liner:
– Most end-users buy a Sea toSummit liner specifically because of its light weight and small packed size. A zipper would considerably increase the weight and the packed volume.
– A zipper in a sleeping bag is there to ‘vent’, to help control temperature. If your concern is your sleeping ‘environment’, you should know that the Silk, Silk/Cotton, Reactor and Adaptor series all wick extremely well, and allow enough air to pass through to keep you really comfortable.
– If your concern is feeling constricted in a liner, you should choose the Coolmax Adaptor. The fabric is extremely stretchy and very soft – you will hardly notice you are sleeping in a liner at all.
The Reactor Fleece Liner has a 1/3 zipper, and the Toaster Fleece Liner has a full-length zipper. The Reactor Fleece Liner is an extremely warm liner and a great stand-alone summer sleeping bag. It’s packed volume is 2.5 Liters.
The Toaster Fleece Liner has a large packed volume (5 Liters) and therefore is often thought of as a lightweight sleeping bag rather than a liner. (A Toaster is great for hut tours, or river/desert trips where easy care is important).