OUT OF STOCK NOTE: The nipples are in extremely short supply. We ask that our customers only order 1 package so that we will have enough for everyone that needs them. We are hoping to see the Silicone Nipples in the near future, regretfully the manufacturer has told us that they will not be available for 3-4 months but we are hoping to see them far sooner than that. We apoligise for this shortage though it is out of our control. We have a large supply of Catac ST1's in stock to take their place during this shortage. Catac ST1's were always everyone's favorite before the Silicone nipples existed so hopefully they will get us by again. Chris This is nipple set is recommended by Chris to be used on young squirrels up to 8 weeks of age. This nipple set comes with five nipples and two silicone o-ring syringes. This nipple has a pre-made hole which is very small therefore there is less chance of aspiration. Chris recommends switching to the PetAg elongated nipple from 8 weeks and up. This nipple set also works well with other small nursing animals such as bunnies, skunks, opossums, small breed puppies and other nursing animals of similar size.