The bern morrison helmet is bern39s first attempt at a mountain bike specific helmet and as expected they39ve done an excellent job this relatively lightweight lid has a pvc microshell lined with their proprietary zip mold liquid injected foam this creates a low profile design with a slimmer shell which won39t sacrifice any protection aspects the helmet has 16 vents offering twice as much airflow compared to bern39s other leading models this all mountain helmet has a twist