These socket extenders are used to lengthen an existing socket when its position is fixed in an HID lighting reflector. Most modern reflectors are optimized for longer 1000 watt lamps. This allows a user to better position a 250 to 600 watt lamp in these reflectors. For use with 250-600 watt lamps. DO NOT USE WITH 100W LAMPS. 4KV pulse rated. Extends socket 2-3/8 Inch.