1.Disposable Replacement Dr.Pen Nano Round Cartridges for Dr.Pen A6S Microneedling Pen 2.Dr.Pen A6S cartridges are developed based on the highest American standards. We are confident in our dermapen cartridges and offer risk-free money back guarantee 3.Bayonet slot Maximum diameter 0.25mm is compatible with skin texture 4.Individual packaged: Each individual cartridge is individually sealed in sterile packaging. Dispose of cartridges after each session. 5.Package includes: 10 pcs replacement cartridges / needles for Dr. Pen A6S Microneedling Pen.