241 New Men's Mineral Watch Crystals & Hypo Cement. This is a new set of 240 men's flat mineral watch crystals in 20 different sizes. Each flat natural mineral watch crystal measures 1 mm thick. You receive twelve of each size: 26, 26.25, 26.5, 26.75, 27, 27.25, 27.5, 27.75, 28, 28.25, 28.5, 28.75, 29, 29.25, 29.5, 29.75, 30, 30.25, 30.5 and 30.75 mm G-S Hypo Cement. This is a new tube of G-S hypo cement. This adhesive is great for knotting between beads. It will keep knots from fraying. Excellent for jewelry making and beading. The precision applicator allows for precise amounts of cement to be applied to intricate parts for neat and precise work. It contains 1/3 oz.