The Morris Products 21722 Plastic Knockout proved to be a disappointing purchase. Despite its claims of being an efficient and durable product, this knock out was a major let down. Thanks to my knowledge gained in practice as a professional in Industrial and Scientific equipments, I was extremely dissatisfied with its flimsy material that immediately broke on contact. The only positive aspect was the affordable price, but ultimately the knock out's poor quality made it a waste of money.