Built-to-order torsion springs for self-storage and mini warehouse doors. These springs are made to your exact measurements in the USA and shipped after production is complete. Because they are custom, they are not returnable or exchangeable, so double-check your measurements before ordering. Self-storage doors see a lot of cycles since tenants open and close them constantly, and these springs are built with that in mind. You will need to know the wire size, inside diameter, and spring length when you order. Contact us if you are not sure about sizing. Standard residential torsion spring dimensions do not apply to mini warehouse doors.