John Deere GX21582 Extension Spring is designed for use on many John Deere 100 series mower decks. This John Deere equipment manufacturer (OEM) part ensures reliable performance and compatibility. If you need help finding the right John Deere part or accessory, John Deere specialists are available Monday through Friday, from 8:00 AM to 5:00 PM (EST), by calling 800-345-2396. You can also contact a specialist via email through the provided support channels. Hartville Hardware strives to provide accurate part recommendations sourced from reliable systems, but since parts and compatibility can change without notice, it is to contact Customer Support if you are unsure about the part needed.