821 Fisher / Blizzard Compression Spring Plow Pin Meyer Diamond 814000005

This spring is used on a number of plows over a 1" pin.

Blizzard and Fisher both call it Compression Spring # 821.

Meyer and Diamond use it on the MDII, Plus and old Diamond plows as 814000005. 

This spring is used on the headgear for Minute Mount 2 plow systems. It is part of Connecting Pin Kit # 27168K.

For an example of it's placement, check this document.