Fire-Rated Door Fusible Links | McMaster-Carr
To ensure safety, replace links annually and do not paint or coat them. Use links in straight-pull applications only. Style 1-5 links are for use on fire doors, windows, and lids. Style 6 and 7 links are often used on fire doors, windows, hatches, dampers, and blowers. Style 8 links are commonly used on fire doors, smoke and heat vents, and ducts.