NEW Arc'teryx Calidum 5 Panel Hat in Velocity, a light Purple, looks most like stock photo (first photo). New with tags, excellent condition. One size fits all. Performance five-panel hat with a classic look and comfort stretch. The Calidum is a little different. We took the classic five-panel design, then made it with the same performance structured mesh we use in our Konseal climbing harness. The result's a durable, breathable cap that works anywhere – pushing it on the trail, hanging out at camp, and resupplying in town. The material's stretch forms to fit, and the back secures with a TPU strap and buckle.