On'h Nurse Penlight LED Medical Pen Light with Pupil Gauge Measurements (Red+Silver, Warm Light) Dual-function pocket clip for portability and for activating the light Click and it holds, extra bright sealed concentric beam. Long-life and reusable, easy to use and affordable. Reusable LED penlight with sealed concentric beam to illuminate the eyes, ears, and throat Included replaceable AAA batteries, Penlight sise: 13.5cm (5.3")Length x 1.3cm(0.51")diameter, LED color: warm white and pen color: red or silver.