max diameter: 62 mm
For this flashlight:
Reflector 38 mm OP.
LED: MCE serial.
Onemode driver for input voltage near 12 V (two batteries for this flashlight: 12 V 2200 mA and 4400 mA).
For U(in)=14V I(in)=0.75 A driver has U(out)=13.1 V I(out)=0.66 A
For U(in)=12.17V I(in)=0.84 A driver has U(out)=13.09 V I(out)=0.65 A
Not bad as for me (83%).
summary angle 66 degrees. Central: 14 degrees