Gird your harnesses: After a six-month renovation of the Puck Building and what feels like years of preopening hype, the outdoor-gear superstore REI is launching its first New York location on Friday (303 Lafayette St., nr. Houston St.; 212-680-1938). Snapshots of climbing and kayaking excursions now collage the historic space’s former ballroom, and a new spiral staircase winds two stories down to a full-service bike-and-ski shop. In addition to several hundred brands’ worth of apparel and gear for snow sports, camping, cycling, climbing, running, paddleboarding, and errant wilderness wandering, the 35,000-square-foot, three-level behemoth will attempt to convert EMS and Paragon devotees with extras like a snowboard shop and the REI Outdoor School. The first 200 shoppers each day over opening weekend will receive a free CamelBak water bottle containing an REI gift card worth from $5 to $100.