LED light buying guide
LED Bulb Base
LED light bulbs are mainly use MR16,E27,PAR30,PAR38 series,you could shop for the LED lights by search the base.
1.MR16/GU5.3: Multifaceted Reflect, multi-faceted reflector (light cup), the figures behind of the cup lights is to show the max outer diameter (unit is 1 / 8 inches),   MR16 ,The caliber = 16 × 1 / 8 = 2 inch ≈ 50mm
2.GU10 : G type lamp,it is a plug-in,U mean the part of a U-shaped lamp,the figures behind of the lights is to show the center distance of pin holes (unit Is mm "MM").GU10,mean 10mm of the center distance of the pin holes.
3.PAR Series:Paraboloid aluminium reflector
PAR:echo shape of paraboloid,the figures behind of the lights is to show the max outer  diameter(unit is 1/8 inches)
PAR38: the caliber =38*1 / 8*25≈ 120mm
PAR30:the caliber=30*1 / 8*25 

4.E27 :Threaded screw lamp holder
The figures "27" to show the diameter of the threaded screw lamp holder.
E27 is the 27mm diameter of threaded screw lamp holder