The GBSSR1 is based on the popular SP- Lite2 pyranometer of Kipp&Zonen. It contains a SDI-12 interface / data acquisition board potted inside a cavity in the base of the housing. Consequently the GBSSR1 comes in exactly the same form factor as the original SP- Lite2. The sensor offers a resolution of 0,25W/m2. It is already calibrated to the individual sensitivity of the SP Lite2.