An all-in-one craft bowstring care kit. Created exclusively for crossbow strings, BlackHeart&';s premium string wax not only protects your string and cables from natural weathering effects it also deeply penetrates the string fibers, conditioning them. UV impervious. Applies clear. 1oz. tube. BlackHeart&';s premium rail lube creates a slippery surface for your string to glide across vastly improving shot consistency. Reduces center serving wear. Idea viscosity for application. Increased velocity. Scent-free formula. 0.5 oz bottle.