64 titanium needles 0.25mm 0.5mm microneedle hydra roller dermaroller derma roller with gel tube

the standars of 20 pins derma stamp as following: 1. length of needle: 0.25mm, 0.6mm, 1.0mm; 0.25mm for home use; 0.6mm, 1.0mm for professional clinic use. 2. number of needle: 20 pins; 3. packing: blister packaging + carton;