The Bastion Helmet from armor R&D firm Diamond Age was designed with the SWAT officer in mind. It's the first helmet to offer protection from all common rifle rounds, at all conceivable velocities. Backface deformation against the M855A1 at 3050 feet per second was recorded at less than 10mm. The Bastion is essentially a lightweight, high-end combat helmet that's up-armored with a modular ceramic and carbon fiber exo-shell. This exterior shell is comprised of five separate tiles: A front, a back, two sides, and a top. These shell tiles are all removable, and they can be mixed and matched to suit various tactical purposes; e.g., a sniper may choose to wear only the front plate, whereas a tactical team officer on a breaching raid may want to wear a fully-ceramic-clad helmet, for maximum protection.