The Amazon rollers may not be well made. It is really easy for the needles to become dull or bent or harbor bacteria, which can be dangerous. If you would like an at-home roller to use, we recommend the Gold Roller on theskinspot.com. Gold is antimicrobial and the roller should be cleaned between uses. The cleaning fluid is also available online. The Gold Roller needles are not as long as the ones that I use in a medical microneedling procedure like Vivace or Morpheus8. The longer needles produce much more dramatic results.