The sizing and glue issues are what dropped two stars on this rating. I purchased Soft Claws kitten size, which includes kitten and small size caps in the package. I also had previously purchased Soft Claws small caps in a local store, and I purchased a cheapo variety from Amazon called Dadiii. Overall I like the caps while they are on our kitten and not falling off. Hightlights and Comparisons: Soft Claws Kitten / Small size: $15-16 for 20 Kitten caps and 20 Small caps OR $13 for 40 small size caps with CLS Includes dried out glue (see reviews) All caps (kitten and small) seem to be the same size. The caps that are slightly bigger in the kitten pack seem to be the biggest out of both packages but appear to have no CLS*. The "Cheapo" variety (I bought Dadiii) $10-12 for 120 Nail caps Glue WORKED No CLS* If you want more wordy info: *CLS, or Cleat Lock System, defines the interior of each cap, which has a step design to keep the cap from falling off as easily. The step design also holds glue well and seems to aide in holding the cap to the cat's nail. I haven't seen this design idea with anybody other than Soft Claws ( I did look) The Kitten size arrived later than the Small size variety, since I picked up the size Small at a local store. I was very disappointed in the Kitten size - it looks EXACTLY the same in sizing (width, length, and diameter intended for the nail). I can see no difference. In fact, the kitten sized nail caps included both kitten and small sizing (assuming you wouldn't need kitten size caps for long I guess). The size smalls included with the kitten pack were very slightly bigger than the other size smalls I had previously purchased. I was also VERY displeased to note that the kitten/small caps package did not include their Cleat Lock System (CLS) on what I assume is supposed to be the size small caps. So CLS for kittens, but not for small cats? My other pack of Soft Claws included ALL CLS style caps. I'm confused why this was changed with the kitten package. The ones without CLS look super cheap (I did better with the cheapo package I bought) I can only conclude that Soft Claws is phasing out their kitten caps and working on S, M, and L only. But I am very displeased at having spent extra just to get the smaller caps, hoping they would fit better and stay on better. The kitten caps were more expensive, and I already had the other size, so I felt like I wasted money on this. A chart of the TRUE sizes would have been beneficial. Also, I cannot get these to stay on my cat. Granted, she is persistence itself - she gets many off in the first night after an evening application. She worries them and chews them and can't leave them alone -- so I can assume I will have to continue applying them until she gets used to them. I may also have to trim the caps to make them a little shorter (maybe more comfortable?). Perhaps they won't stay on due to the glue - the first pack I used, I didn't know what to expect. The glue was incredibly difficult to get out (it was partially dried out I later realized). The cheapo pack included glue, so when it came in, I grabbed their glue and tried to apply the missing caps to my kitten. Marvelous. it worked. This glue smells like super glue. I will have to look it up and see if it is the same. Since the cheapo pack included many more nail caps, and fresh glue that worked and wasn't dried out (many other reviewers have complained of this) then I can say that Soft Claws' glue has issues. The first application might've gone better if the glue had worked and not taught my kitten that she could get these off. More caps stayed on with my second application with fresh glue. Application wasn't too hard, all things considered - I have been working with our kitten to be handled and have her nails filed since we got her. We still had to use a towel- she doesn't like the feeling of these caps beeing pressed on the end of her nails. She was pretty calm through trimming her nails, etc until we started pressing nails on. All of these annoyances stated: these caps are marvelous while they are on. Nobody gets scratched, it is training the cat not to scratch us, the furniture, or use her nails to climb furniture or mattresses. I love the training element and I love not getting scratched. The cat is young, perhaps she will grow out of some of the problems we've had with her claws, since most of the issue is playtime (or the cat imagines it's playtime). But if these caps don't start shaping up, I have wasted about $40 on various types. They better work long term... if they do I will love them. If they don't I will be angry at money and time wasted...