bayonet coupling 9 pin needle cartridge for auto microneedle electric pen 0.25~2mm tips nutrition input

needle material : stainless needle. micro needle length: 9 needles (0.25~2.0mm). you can adjust the length of needles and the vibrating frequency, according to your need( 0.25mm,0.5mm,1.0mm, 1.5mm,2.0mm).