It is an old model or a product that we can no longer order at the manufacturer.
The Polycotton is a Sleeping Bag Liner from the brand Sea to Summit. The Expander liner is made from premium stretch-knit polycotton. This construction provides excellent elasticity and more warmth compared to a standard cotton Sleeping Bag Liner. Allowing you to move freely during the night, its controlled antimicrobial treatment keeps bacteria at bay. Why go without it?
Polycotton - Standard
Polycotton - Double
Polycotton - Traveller with pillow
Polycotton - Mummy (with hood)
Polycotton - Long