I used the model that gabeknuth made and just shortened it to make the smaller piece. As the picture shows they are interchangeable with the original construx only I would have to say much stronger. They are kind of hard to snap on at first I found after about 10 uses they are pretty much like the original. I hope to remake more of these, not necessary all of the construx pieces, but most of the basic ones. Like it if you care, it might motivate me to do more.