I LOVE these Markers and so does Harrison. I am always looking for something new to add to my "school work" bag of tricks. I DON'T LOVE markers but all kids love them. The thing with these are is that you just twist to open so there is no top to loose. And The twisting is the fun part so Harrison always wants to make sure they all are closed. NO MORE DRY MARKERS OR LOST TOPS. I don't know how long these will last but we have had ours for about a month and they get used daily and they are still going strong. I got a pack just like this one for $3 at Big Lots.