The JDS1644 3-Pt Lower Link and Spring is specifically designed for parade tractors. It holds your lift arms together when you don't have an implement attached so they aren't flopping around.
JDS1644 3-Pt Lower Link and Spring fits John Deere: 40H, V, 40 S (sn 69582 and up), 40U (SN 62734 and up), 320, 330, 420H, 420S, 420U, 420V, 430H, 430S, 430U, 430V, 1010RS, 1010 UT
Yellow cadium, Spring is 8-1/2" overall length (Includes 2 hooks and 1 spring)
Replaces: M2733T, M2734T
View the John Deere parts manual page for the spring location on the hitch.