Never worn! The Crye Precision Halfjak is a specialist bit of kit. So specialist, in fact, that I know very few people who own one. So what is a Halfjak? As the name suggests it’s a ‘half jacket’. A lot like a viper hood, it covers head, shoulders, arms, back (or small pack) and upper chest. So, rather than carrying the additional bulk of an outsized jacket to wear over your PC during inactive periods, the Halfjak strips things down to the bare essentials; while also allowing you to access your mags etc. It’s difficult to estimate the insulation fill, but it seems to deliver an Atom LT level of warmth when used in conjunction with a PC. Not waterproof but does offer some protection against the rain. ☔️ The jacket’s insulation runs throughout the arms, shoulders, chest and upper back. The lower back and helmet compatible stowaway hood are uninsulated, but feature the same wind resistant shell as the rest of the item.