Apollo Horticulture Purple Reign 10W A19 LED Grow Light Bulb for Plant Growing 1 - Apollo Horticulture 10W A19 LED Grow Light Bulb Dimensions: 4" Height, 2" Diameter / LED Wavelength: Red: 600nm - 650nm, Blue: 420nm - 500nm Attain optimal photosynthesis - purple light combines ideal red and blue light spectrums for healthier, more abundant grows Plug-and-play - fits standard E27 sockets for easy installation, no special hardware necessary Discreet design - looks like regular incandescent bulbs and fits into many standard home appliances