Hot Water Shroud Kit for Kirby Morgan SL Helmets MK-21 & KMB 1828. The Hot Water Shroud (Part, 525-100) should be used whenever diving operations are conducted on mixed gas or when diving in cold water. Tools required: 1. Flat Blade Screwdriver 2. 78 inch open end attachment on torgue wrench 3. 1116 inch open end attachment on torgue wrench. The shroud helps warm the divers incoming air thereby lessening divers heat loss.