The Spada Crucible Baselayer Crew Long Sleeve base layer top is made from lightweight fine-knit polyester with elastane, with a soft, brushed interior to trap heat and aid moisture control. The super-smooth outer surface allows outer garments to glide freely over the base layer, and lightweight stretch mesh panels running down the inseams improve airflow. The self-fabric collar and cuffs gives superior comfort and a custom fit, and the true-flatlock seams give superior comfort.