They will only work for straight posts with wearable of 1/4" or larger. They will also only work for clickers that have a post that measure EXACTLY at 16g (1.2mm).
When paired with a post with a wearable larger than 1/4", they will have room to move side to side but can still be worn with that clicker. If it is difficult to insert post at one side, try to insert through the other side.
These expanding posts are guaranteed to work with Metal Mafia clickers. Clicker here for Metal Mafia clickers.