Provides the right condom size - but also works to meet the right amount of spaghetti.
For the right condominium size:
Stop the muzzle in the hole where it is just for the location and read which condom size this corresponds to. As simple as that!
For the right amount of spaghetti:
Take a fist of spaghetti and select one of the holes. King Size if you are hungry and trim if you are just a little crazed. Insert as many straws as you can into the hole you have chosen and then follow the cooking instructions.