Hand built one at a time, Sweetpeas have a 1/2" hand poured resin toneboard and a machined barrel with 1/2" bore. This a small, medium range , finesse type call that is great for bobcat and fox calling. Awsome on coyotes as well. Easy to blow call with a high pitched, tight brassy tone with a little rasp built in. Your not going to put a lot of air thru this call, but it's effective for what it is built for...close range, high pitched calling.