Technology driven for active kids in cold weather, Columbia's Midweight Crew features Omni Heat and Omni Wick to keep kids warm, dry, and comfortable. . Soft polyester interlock fabric with Omni Heat and Omni Wick technology. Omni Heat thermal reflective with little silver dots helps regulate temperature by reflecting and retaining the warmth your body generates allows sweat and excess heat to escape. Omni Wick pulls moisture away from the body to evaporate quickly, keeping kids dry and comfortable. Antimicrobial treatment for odor resistance. Inseam: 21 in.. Body skimming fit with end use mobility in mind.