I would assume its a proprietary size, even though it fits in a 3xAAA slot.
Don't be a tight arse... its 25 quid! Buy a Chinese Amazon-special head torch if you find 25 quid too much for a high quality and innovative torch battery.
Fri Night Vid Why the Evolution of Indoor Bouldering Gyms is Changing Us
This week's Friday Night Video is an in-depth look at the evolution of indoor bouldering walls by YouTuber Hannah Morris. As the discipline soars in popularity, we are in a golden age for indoor bouldering.
There are a...