These are plastic reflectors made to fit the T5 fixtures by snapping on under the bulb.
Stop wasting valuable UVB and reflect it back into your dragons enclosure with a reflector. Over 50% of the light emitted from your UVB never goes to use, reflectors are proven to increase the available UVB and increase the output up to 50% more than normal.
Great for baby racks and custom enclosures!!