What Is this??

Okay so its been about 10 years since I was really into astronomy and have recently gotten back into it. Thankfully I still have most of my books and I am pretty sure my Sky Atlas 2000.0 is still at my parents place(I have to locate it next time I am there). I do remember however when I bought my sky atlas I also picked up an accessory that is a small triangle of acrylic that had something to do with the sky atlas. It has what looks like a telrad reticle, magnitude gauge, arcsec/degrees, and a small magnifier. It says L-5 Systems on it and I can't find any references to this product on any of the sites out there.

I have attached a photo and am hoping that someone knows what this is and can help me get some more info about its use as I have completely forgotten how to use it with my SA2k.

Thanks.

Attached Image:

The circles are to show what a Telrad would show looking at the sky. The - and + show the magnitude of the stars that correspond to that size on the chart.
The other numbers correspond to degrees on the chart.