I have used this lance system for 2 years. The white lancets are the thinner gauge lance option for the OneTouch Delica Plus lance. Thinner than the gray ones it ships with, they are good for people who have very thin, sensitive skin. The gray lancets are slightly thicker gauge which will work somewhat better for thicker or more calloused skin. But the Delica Plus lance lacks the true oomph to make a good deep, firm stick. I would call it a gentle lance that doesn't go very deep. I like it because it's very easy to use and it has a pushbutton release to eject the lance rather than make you struggle to pull out the used lance and maybe stick yourself a couple of times while attempting that. Compared to my TRUEDraw lance, the OneTouch Delica system (with either gauge lance) doesn't give a deep penetrating stick. So, if you have delicate thin skin, you'll probably be good with these lance tips and the Delica Plus lance, although don't be surprised if you must dial it up to the 6 or 7 max in order to get a good stick. If you absolutely require a good firm foolproof stick from your lance, then I recommend something like the TRUEDraw lance %26 the budget friendly 100 pc box of ReliOn 30 gauge lances that are only $1.94 for a box of 100, especially if your insurance doesn't cover diabetic test supplies. The TRUEDraw is more difficult to load a lance into and remove the used one from, but it never fails to stick me better than the Delica Plus, even on the lowest 2 settings. Sometimes you have to try a couple or three lance types before you find the one that doesn't hassle you too much. My insurance keeps switching the preferred brand around, so last year it was One Touch but this year I had to switch to TRUE METRIX.