M&M Cage Company Programmable Sunrise Sunset Dimming Timer, Works on Any M&M Cage Light Light, 

Plug this timer between your M&M PetLight and its power adapter, set the on and off time and your light will gradually turn on and off over a 20 minute period instead of instantly. Simple to program. Large, easy to read LCD monitor with Hr/Min/Sec. Time accuracy: +/-2s/Day. 12 or 24 hours options. Battery backup stores program during power outage. Maximum load: 24W (2A @ 12V). Wide range voltage input：DC5V-30V.