Doug Fleenor DIN Rail Mounted DMX Opto-Isolator
Details
The DINTAP is a DIN-rail mounted DMX512 optical isolator. The output is electrically isolated from the input by a 750 volt DC to DC converter and a 2500 volt optical isolator. The DINTAP allows the DMX signal to be split without the possibility of reflections from one signal path interfering with the signal to a device on a different path. By isolating the output, electrical noise and hazardous voltages on the output are prevented from affecting (or damaging) devices on the input.
dintap-data (1).pdf
Doug Fleenor DIN Rail Mounted DMX Opto-Isolator (Doug Fleenor DINTAP) 
Customer service via phone call was excellent and ordering products online was very easy.
No complaints
Found a hard to find part and it was still affordable. The payment process was a bit of a problem, the system either wasn't working properly or it needs a bit of clarification on the instructions. I did get it paid for and the delivery was fast. Overall satisfied with this purchase.