Is it for biking or just for hiding in? I was under the impression that the SAS were wearing the Mk7 when they wear one, and the Delta one (if you mean the Blackhawk Down one) was a cheaply bought skateboarding helmet with no ballistic protection
No they have new ones that are similar to the impact helmets.. But made of ballistic ceramic, compressed spectra and aluminum oxide powder.. Same stuff the ESAPI plates are made of.. They look like a "Full Cut" bike helmet.. But with attachment points added.. Smaller and lighter, less clunky, but still with decent coverage.. NEW, SWEET!