Our MR16 Reflector Lamps have a pressed glass reflector inside. The "MR" actually stands for "multi-faceted reflector." The interior or reflecting side of the bulb is comprised of facets and covered with an aluminum coating. Our MR16s are available in either a 24 degree or 38 degree beam angle. Unlike MR16 dichroic lamps, our aluminum reflector lamps reflect both heat and light out through the front where it can dissipate into the circulating air. Some of our bulbs have a special cover glass located near the front end of the reflector. This cover provides extra safety for the user in case the bulb breaks. In some cases, it is preferred to use an MR16 without the front glass and these are designated with "NL" at the end of their part number.