Using a clean cloth to hold the lamp, screw the lamp into the E40 bulb-holder fitting of your reflector until it will turn no further. It is important that the lamp is screwed very firmly into the holder. Failure to fit the lamp tightly will cause arcing inside the holder between the centre connector and the contact on the lamp. This will melt the solder contact on the lamp and irreparably damage it. Connect your reflector cable to your 600W HPS ballast. The wattage of your ballast MUST match the wattage of the lamp you are using or there will be a high risk of fires or equipment damage. Ensure the lamp is completely clean and free of dirt, grease and finger-prints etc. before switching it on.