This is a A-81816580 SUB TO SD12 PN: 81816580Main Description As Following : A-81816580 SUB TO SD12 P.N: 81816580 Overall Length: 2.08"Thread: 1/2" - 20 UNFThread Length: 2.08" Stocked As: A-SD12 Found in Section & Models : Tractor Parts Associated Items : New Also This is An Aftermarket Product And : Overall Length: 2.08" Thread: 1/2" - 20 UNF Thread Length: 2.08"