These quality constructed restraining cones (also known as killing cones) are made from 18-20 gauge stainless steel. These make restraining birds for slaughter easier. Large Cones - 10" Wide at top, 18" Long - For Geese and Small Turkeys Medium Cones - 9" Wide at top, 12" Long - For Ducks and Chickens Small Cones - 7" Wide at top, 10" Long Made of stainless steel. In our tests we have liked using the large cone even for broiler chickens. Having it too large is not an issue but if it is too small it can be an issue. The larger cone also makes it harder for the birds to back out. Which can be a problem sometimes. Style may vary.