Has anyone tried these? Any reviews or ratings?

http://www.birds.cornell.edu/courses/home/webinars/?utm_source=Cornell+Lab+eNews&utm_campaign=f858a34a64-Cornell_Lab_eNews_2014_10_09&utm_medium=email&utm_term=0_47588b5758-f858a34a64-302158217#waterfowl

thx jeff b, bellingham