Centec AP-1 Auxilliary Fuse panel. Available thru BestRest for $50.00, it's worth every penny!
It has five (5) individually fused circuits, meaning that you can wire in 5 different accessories, each with a different current rating. Measuring only 2.5" wide, 3" long, and 1.25" high, it provides a professional and convenient method of routing additional circuits and accessories. Overall rating is 60 amps.