The Shock Caller?is a short-reed call, which reproduces all the sounds of Canada geese. This call is so easy-to-blow, you will be able to master it in no time. It enables you to call with minimal back pressure. To keep the call from sticking, due to moisture, we have crafted it with patented ditches on the sounding board. They'll be Shocked it's a Caller. Easy to blow. Machined aluminum collar.