heat tape

Im not sure if this is the right thread but I am putting together a rack and the shelves measure 48" how would I order the heat tape? I see on the different sites where it gives you how many inches but is sthere a way to order 3 48" pieces already set up?

you order heat tape ( flexwatt) in the total number of feet you need ( unless you are geting them to assmeble it. ) so you can order it ( depends on were from via the phone / online and say you would like either 12 ft and wire it your self or if they wire it that you want it set up with 3 4ft pieces . then I still tape and pound the connections ot make sure set ( I solider mine )...