Solid State LED light source surrounding the nib of the pen, it illuminates the writing area only allowing notes or modifications to be made in low light/dark conditions, discreetly.

Ref: NWP

The 'Active Safe' LED Harness has been designed to provide the wearer with 'Ultimate Conspicuousness' in poor weather and light conditions.

Visible up to 500M.  Powered by 3 * AA battery Cells (not provided) for 60 hours continuous use.