I'm using these to build my warm box for printing ABS. If you're unaware, you just build a box around your printer to keep the air warmer. I'm going to install a couple small incandescent bulbs in mine, cause my printer has trouble keeping up with the heat requirements of ABS.
Also, sorry to anyone who uploaded my last 3-way connector, I realized too late that it was the wrong size. The last size fit inside a 1/2" pipe connector.... oops.ENJOY!