DEALS IN CFL, CALCULATORS AND HEALTH CARE PRODUCTS. Cenzer is the energy-saving lamp makers outsource glass, lamp tubes and ballasts, making quality control for these parts difficult. At Bistec Lighting, we have separate glass, lamp tube, and ballast and assembly facilities - so each component of your lamp is made in-house, ensuring the quality you require. That's why Havells, Phillips, Crompton & Greaves and Anchor trust their OEM needs to us.