I have used these on three different albums from different companies! This is a great discovery! There are six extension posts which means you can use on package for two albums. My layouts are bulky, so they take up a lot of room in an album; these posts accommodated my albums with 20 page protectors (40 layouts) easily.
I have tried the snapload system,and was not fond of it, as it made my cheaper albums loose. I think these extension posts are a much better buy!
I was pleasantly surprised at how long these posts actually are. I'm really excited to use them as my next album will be much easier to assemble and stronger as I won't have as many posts inserted in order to have the same thickness result. Very happy I bought them and I will buy them again.