DESCRIPTION This is a universal part that is used primarily for both trash chutes, and more specifically Laundry chute Hopper discharge doors. The reason it is universal is because with this chain link feature, you can cut the chain to the size you need for your door. This same kit can be used on guillotine type horizontal rolling discharge doors as well. A fire inspector looks to make sure that your linen chute door or rubbish chute bides by the nfpa code that mandates that you have a 165 degree fusible link attached to your discharge door, and this kit is in compliance with this code. FUNCTION: The fusible link solution with chain is supposed to keep your discharge door open, and if you have a fire in the basement area of where your discharge door is located, when the ambient temperature reaches 165 degrees Fahrenheit, the fusible link will melt and break apart to allow the chain to be loosened and have your door slam shut avoiding the smoke and fire from going up the chute. WHAT YOU GET: What you see in the picture is exactly what you will receive including 1) Chain Link that measures 30 inches in length. 2) Fusible link rated at 165 degrees made by Elsie, 3) Two mounted S hooks, and one spare S hook. (M60502 / ACMFLK) COMPATIBILITY: All chute door manufacturers including Midland Chutes, US Chutes, Action Chutes, American Chutes, Chutes International, and others.