Experience the safer, more convienent alternative to traditional spectrum tube power supplies. Eliminate exposure to high-voltage contacts. Special break-resistant, polymer-encased spectrum tubes must be correctly inserted before current flows through them. Tubes run continuously for hours, allowing more time to view and analyze spectra. Holds 8 tubes and allows you to select and energize each installed tube, one at a time. Only use with Safe Spectrum System tubes. Includes instructions.