If you need 90 degree positioning angles these are for you. I use 99 cent center spring clips with them, they fit well and are good for making cabinets or gluing shelves together. HOWEVER challenge the form, these are NOT good boomerangs, if you drop them expecting them to come back you will be disappointed. Luckily, as a full-time boomeranger and part-time carpenter, I was still able to use them.