Oh pshaw, on Sat 26 Jan 2008 11:50:14a, james meant to say...
I'm not sure why you're posting it in rec.food.baking... But I believe it is used in conjunction with infrared remote control in either with either audio or video equipment.
I had a similar device that was plugged into a special jack on the back of my TV. The other end was placed in from of the infrared received on the front of my VCR. Using this I could automatically schedule recordings from the TV Guide signal that was picked up by my TV. The scheduing was done from the TV and transmitted to the VCR.