LEGO Techniques - DUPLO Cactus

Not a very technical discovery and not a very long post but the DUPLO cactus caught my eye the other day and I decided to try it with some Primo.  Of course it fit like a glove.  Too bad those arms aren't more System designed.  They are about 18mm inside which fits a Bionicle Zamor Sphere nice and snug.  Don't blame me if yours gets stuck in there.