As Steve said, you need the other components. There were actually 3 different dealer-installed speed control systems. I don't know which one you have, but I'm sure it isn't the first one since this is a pic of that one:
But here's a pic from the '86 Accessories catalog, and this one looks like yours:
And here are the part number listings. You can see that the first two systems were from Dana, and the third one from Specific Cruise Systems. I think that's what you have.
Gary, AKA "Gary fellow":
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Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI