These are 2oz of Brine shrimp direct baby brine shrimp eggs that have had the outer shell removed. They can be hatched like normal brine shrimp eggs or fed directly to fish. There is no worrying about shells of baby brine shrimp eggs to separate or strain out from the collectible culture. Will last indefinitely in the brine solution until you are ready to use. These are very expensive online and only a few companies have them available.