I usually take a medium but picked up a large in store which fits. The ratchet is tight so hopefully I can kit a beanie on underneath. Finish on the helmet is good and it's a bargain at the price. I much prefer it to other brands up to £60.
I like that the forehead pad wraps around the plastic mount so no sharp plastic edge is exposed. My last helment, like many, mean that on impact the edge easily digs into the skin which meant 7 stitches on my last (not btwin) helmet.
Rear staps on my mine are a little lose and not adjustable. The ratchet keeps the helmet secure enough though.
It would be nice if Btwin sold replacement pads so I could swap them out as I wash them and still use the helmet.