Its stable, fast, cheap ink and amazing quality! I found that its best to roll them super tight, place them in your ear and then wiggle the top of your ear back-and-forth with your hand until it fully expands. This small size (blue color) is big enough for my Klipsch R6i II in-Ear Headphones AND their cords AND the clip AND the control button AND the lightening adapter needed for my iphone 8. For ref: my 13 month old daughter who is just learning to walk wears a size 4 shoe and the 2-3M fits her perfectly with no room to grow. Aside from that my daughter loves them! I have a pretty skinny foot. 5v:2. Anyway it;s not that difficult to figure it out but you may be wasting time to screw/unscrew couple of times. I didnt test them to see if they would, but adding any more weight to the rack beyond its fixed rails would just make the movement issues worse. Im a cook so Im on my feet 8 to 12 hours a day and my back or knees or feet dont hurt at the end of the day.