That is meant for warming motor oil. I would be leary of putting wort through it as you never know what residues are on it. Also, iot only works by convection so you'd need a pump with it too.
Every rims tube that I know of needs a pump. But yea that was my only concern being food safe, would be interesting to check into though if I could check it out before buying it. That's a good deal for a full enclosure with a element.
I recently built one from 3/4" SS fittings from amazon and a stainless 800w cartridge heater. Cost was right around 35-40$ if I remember right. Haven't had the chance to use it yet because the cartridge heater took 2 months to get here from China.