easy to install on any angle [SEP] these didn t come with instructions so when i took one apart to add catnip it was difficult for me to figure out then i noticed a small notch on one of the pointed ends was able to get it back together the adhesive double sided tape seems very strong my cats were immediately curious about them one has already rubbed against one i call that a success i will say that the catnip is very messy but again there were no instructions so i am not sure i ve installed correctly