Green in color, defines 21 needle gauge. 1.8 mm depth. Automatic needle retraction and lock out ensure sharp edge is enclosed before and after use. Convenient, intuitive, one-step activation for precise and consistent results. Color coded design for quick and easy identification. Ready to use right out of the box; no set-up required. Ergonomic, rounded shape and no-slip ribbing on grip make lancets easy to handle.