F21T5/41K : 21W T5 Linear Fluorescent Lamp, 34", 4100K

Standard E-Lume 21W T5 Linear Fluorescent Light Bulb. Sold individually. F21T5/41K/8/PS/G5/ELUME #59191

Preheat Lamps are a starter type fluorescent where the cathode filament is preheated before any high voltage is applied to start the lamp. When the power supply voltage is applied, the starter begins discharging, the starter contact closes and current begins flowing to both of the fluorescent lamp's cathodes. The cathodes are preheated, and begin emitting electrons. There is no heat generation when the starter's bimetal and fixed electrodes close and a current flows. Therefore the bimetal cools and returns to original position, thus opening the contact. The large kick voltage generated by the ballast lights the lamp.

The colour of light radiated from a fluorescent lamp is determined by the chemical composition of the phosphor coating on the inside wall of the lamp. Cool white 4100 Kelvin increase the contrast on the page when reading, making them ideal for work areas such as office spaces, public areas and home task lighting or for showcasing merchandise.

Fluorescent lamps provide the following advantages:
Low operating costs
Long life
Excellent light quality
Superior CRI
Increased lumen maintenance