Designed to ensure superior strength in wind and snow, the Mountain Hardwear Trango 3.1 tent uses extremely durable yet lightweight fabrics and materials. Evolution Tension Arch: panels of low-stretch fabric along the pole connection arcs reinforce the pole structure and stabilize the tent in 3 dimensions. Atlas Scandium XL poles are very light, super strong and completely field serviceable without tools. Additionally, these tough XL poles come with subzero Shok cord and heat-treated aluminum threaded pole tips. 2 large D-shaped doors let you choose between mesh for ventilation or ripstop nylon for 4-season use and privacy. Full-length vestibule pole creates a large front vestibule area and adds strength clear UVX film window is rip-proof and allows views outside. Tension Shelf supports the vestibule pole which greatly increases vestibule volume, adds structural strength and offers overhead storage. Rear vestibule offers an extra entry and extra storage space for gear zipper allows access to rainfly for roll-up ventilation. Dry-entry vestibule design prevents water from dripping inside tent when vestibule is open, improving livability. Upper canopy through-vent has mesh panel for airflow and ripstop nylon panel for 4-season use. Expedition nylon taffeta rainfly features a polyurethane coating on the inside and a silicone coating on the outside for added rip- and UV-resistance clear SVX film window. Expedition bathtub-style nylon floor features a non-hydrolyzing polyether urethane coating, making it one of the strongest floors available. Internal guy system provides additional rigidity to the structure by creating resistance to the flexing and deformation of the frame. Other technical features include reflective guyout loops, reflective starter point, welded guy clip anchors and superlight 1/4 in. buckles and webbing. Stake-out loops are large enough to accept skis and snow pickets.