Rotary Dose Lock Clamping Pen Shell Reusable Metal Pen Holder for 3ml Cartridge

Rotary Dose Lock Clamping Pen Shell Reusable Metal Pen Holder for 3ml Cartridge. This pen features clear dose display and intuitive adjustment, delivering comfortable operation and high user approval. Adopts proven structure for gear shift and dose control for reliable use. Simple dose setting and calibration greatly enhance comfort. Equipped with quick connector and slide lock for fast refilling, compatible with various multi-dose supplies. Designed for easy operation while offering great value for money.