Question on an MRC Controlmaster X powerpack

[cruikshank]

Hi, I picked up two of these recently. (1) brand new in Box, but no manuals.  Relatively easy to figure out, but I'm curious, above the AC in cord is a Brown zip cord, unstripped.  To my surprise it is line voltage AC out.  What was this for, their handheld controllers ?

Thanks,  Dave

[johntanz]

Is it a Controlmaster 20?  If so, then it is probably for the handheld controller.  If not, I'd call Frank at MRC Tech Support.