Just screw the E40 adaptor into the E40 lamp holder attached to the reflector then fit the CDM Lamp into the E40 adaptor. Switch done!

CMH/CDM (Ceramic Discharge Metal-Halide or Ceramic Metal Halide lamps give out an intense full spectrum light similar to natural daylight. These lamps have a different fitting to standard HPS lamps and will require an E40 to CMH/CDM Adapter to be fitted to standard reflectors with the E40 (HPS) lamp fitting for use with aCMH/ CDM lamp. CMH/CDM lamps give you a far fuller spectrum light which in turn gives much better quality plant growth compared to HPS lighting alone.