ONE-CARE PRO DUO Safety Pen Needles offer 100% safe and convenient insulin injections. Accidental needle-sticks are prevented thants to automatic needle shielding before and after use. The back-end needle is protected after removal from the pen for safe disposal. The red-color activation indicator distinguishes between used and non-used devices. The see-through window enhances visibility during priming, while the ergonomic design provides a comfortable grip. These pen needles are compatible with most popular pens on the market and offer cost-saving versus major national brands.