These are the speculums, they come in all sizes. You know what they are for and I'm sure you can come up with some new reasons to add one of these to your toy chest.
Sizes are as follows:
Small - 3/4" opening x 3" length
Medium - 1 3/8" opening x 4" length
Large - 1 1/2" opening x 4 1/2" length
There are no exchanges or refunds on these items (as if you couldn't guess).