Reasonable but more durable The new EXO-391 comes with enhanced safety and durability that can easily exceed your expectations. ScorpionEXO is proud to offer the EXO-391 to those who want the most affordable and safest helmet available. The EXO-391 features a Pinlock MaxVision ready shield that can remedy moisture; KwikWick C wicking anti-fog liners to keep you cool and dry; and Scorpion's flagship Ellip-tec ratchet system for an extra waterproof seal.