The Standard Keil 6416-1012-6401 Glass Globe Plastic Coating 3-1/4\" Dia X 6-3/4\" is a glass structure, which is covered with plastic to trap and spread light inside units. It works through wrapping the light so that there is no direct contact and the chances of breaking are minimized. Its 3-1/4 inch diameter and 6-3/4 inch length make it easy to fit in any standard fixtures and make the lighting assembly enclosed and placed in the right position inside the unit.