31 Aug Glossary PAR 38 Posted on August 31, 2015June 16, 2016 by Flash Parabolic Aluminized Reflector – also known as sealed beams where a parabolic reflector is sealed to a glass or polycarbonate lens. The 38 is a non-matric metric size referring to the diameter of the lamp. It translates to 12.065 cm. MR16 PL