A 4.1mm drive head for ACUS tattoo machines pen type wireless machine "M1". A full set of M1 usually comes with 3 drive heads of 3.0mm/3.7mm/4.5mm, you can easily change the cams and change the stroke at any time. The separately sold 4.1mm drive head sits right in between the 3.7mm all-rounder and the powerful 4.5mm model. As a powerful all-rounder that applies to a wide range of styles, it's practical enough to make the M1 even more versatile.
