These gamma sealed caps are ideal for bulk purchases. They're not that easy to put on at first unless you have a rubber mallet or aren't very strong. My husband really had to negotiate the lids on the buckets they had to fit in. I was sure they would tear or break, but they didn't and he put them on. They used to serve their purpose precisely and ensure the tightness of the products that I buy in bulk. A set of 3 is definitely better than buying them individually.