A single-gang wallbox (3" high x 2" wide x 272" deep) service all individual Skylark dimmers. These dimmers are designed to operate in ambient temperatures from 0°C (32°F) to 40°C (104°F). Allow a minimum space of 472" above and below the dimmer for proper heat dissipation. Energy saver lamps may Not be used with this dimmer. With magnetic ballasts only, do not mix different wattage lamps in the same circuit. Greater dimming range is achieved by operating lamps at full intensity for 100 hours. Use only dimming ballasts shown on chart in step 2 of pre-installation. Do not mix 1 and 2 lamp ballasts in any one dimmer circuit. Do not mix ballast manufactured by more than one company. Using single lamp ballasts produce the most consistent low end dimming level.