Great little device for getting to the back teeth! Sometimes shreds in tight spaces if you're not careful. I liked the Reach (now Listerine) Ultra Flosser even better because of its longer reach, but at 20¢ per refill vs these at 5¢ ea. it's no contest. I keep a pack in the drawer of the end table beside the sofa and floss while I'm watching TV. My gum health is much better since I got these.