Need help with an RPO Code

[Preacher]

I have the RPO code

1SD UPFITTER EQUIP. GROUP

WTH is this????

 

[Rob]

According to our list: http://corvetteactioncenter.com/tech/rpo/8496rpo.html

1SD - Marketed option package 4

 

[scorp508]

1SD - Marketed option package 4

Discussions have brought up that it is the 1SC package, but for Convertibles.