William Lwrote a review of MET Manta Helmet on February 11, 2019
Familiarity: I've used it once or twice and have initial impressions
The Met sizing is prefect for my 55cm head that is right on the extreme end of most other helmet manufacturers. Plenty of adjustment either way with the Met medium helmets for me. I bought this to replace a Met Rivale that got rekt in a hard crash and the fit is the exact same.
Would give it 5 stars, but it is way over the weight that Met advertises - mine tips the scales at 270 grams. Wish it was 200, but I probably still would have bought it even if it was advertised at 270.