I have a love/hate relationship with this tips. The nano-infusion results are great then the actual cartridge fit properly in device. I have been having this issues for a while I'm not sure if anyone else does but its annoying. Herbal Skin Solutions have reached for to me to help me fix the issue but to this day I am still having issues with some of the tips... its like Russian roulette. I have also watched all of the troubleshooting video to assist my efforts. The company is great with aiding me in trying to resolve the issue... its just the cartridges they have too expensive too have the problem. This has made me wary of performing microneedling with my CIT pen, Im afraid of harming someone