I've just bought the British modular sleep system (MSS). Having had both my bags (Summer Vango Ultralite 900 circa 2001 and my Field and Trek Down bag circa 2001) out last year they were lacking and I was quite chilled on one occasion. The MSS is, as has been well documented, a copy of the Carinthia bag. The light weight bag fits inside the medium weight bag to give you a four season option. There are firm warnings not to wash the bag often and when washed 20 times turn it in for an exchange. I don't plan to wash it often and got the liner as part of the purchase. The thing is the liner is shaped to fit the medium bag with tie in's and zips. The lightweight bag doesn't have any such things. So my question is does anyone know of a side zipped, left side opening, sleeping bag liner? I can make one but wanted to know if there was any known before we get my Husky out.