This K Series product has been created for one single reason, to take warmth-for-weight performance to the limit of what's possible. Unique 1000 down, super-light materials, and specific design features mean that the word Ultralight now applies to this wide range of gear that will take you to the Poles as well as on a Sahara Marathon. More on the K Series...

The Omicron “K” is a down filled superlight belay jacket which squares perfectly with the modern fast-and-light approach to technical water ice and mixed test pieces: a good fit, freedom of movement, minimum weight and maximum warmth are essential, but so is dependable protection on cold stances. The stitch through construction cuts excess weight, while allowing the 1000 fill power down to deliver a TOT* rating of -10°C.

Designed to work over or under a climbing harness, the minimally featured, trim fit makes for light movement while climbing. The fully adjustable helmet hood and high front zip provide maximum warmth, and lock right down in gnarly conditions. Minimalism doesn’t come at the expense of function however: this is a highly technical jacket, and the high-viz reflective strips for location, glove-friendly zip pulls and a clip loop to secure the jacket at change overs are all there because they need to be.

Although down filled Belay jackets are really in their element in cold, dry conditions, the water-resistant Ultrashell fabric and YKK Aquaguard zips help to protect against damp snow or dripping ice if the temperatures rise. If you’re venturing into cold and wet conditions though, take a look at our Primaloft filled Belay Jackets.

Please note: this jacket is designed and sized to be worn over the top of outer layers. It provides additional warmth on cold belays and can be swapped between climbers at pitch change-overs. If you want a trimmer, more athletic fit, select the next size down.

*TOT: Typical Operating Temperature

Outdoor photography: Paul Horsman.