Don't think ASOAS ever sold them but you can just find a regular knitted balaclava on Amazon.
https://www.amazon.com/FLYMOON-Winter-Knitted-Outdoor-Balaclava/dp/B08K8LKSY7/ref=sr\_1\_11?dchild=1&keywords=black+balaclava&qid=1625411913&sr=8-11