I fab it from raw material. 1 1/2 tubing, 2- 3/8 half couplings, a 1/4 half coupling for the temp sensor, and I machined a end cap with 1in Npsm threads in it for the heater. The conduit box I made with sheet metal end caps and piece of 3in tube. All 304 stainless, tig welded and electro...