Water-Tight Construction with Unparalleled Warmth. The Drylock series is the warmest, most comfortable suit in the Xcel lineup, made for the most extreme of conditions. Drylock X offers all the same great features as the Drylock, with 3 extra features; expanded range of the Celliant Black, Stitch Free Power Seam Technology, and the 100% waterproof Zipper system. lightly worn. top of the line.