Stack-n-Grow Light System GROWS WITH YOU - The Best Grow Light Technology in a Modular System that Grows with You! Start with the Stack-n-Grow Light System base, and then stack Add-On units to multiply your growing space.Each unit is 31" L x 15-1/2" W x 21" H ECO FRIENDLY and HEAVY DUTY - Frame is 100% recycled polypropylene, Each shelf holds up to 110 lbs., Lights are 36" L, Start 72 seedlings in 3-1/2 sq. ft. of space NO TOOLS and BEGINNER FRIENDLY- Stores compactly in the off-season - Fast, no-tools assembly EXTREME OUTPUT - Includes 2 T5 high intensity full-spectrum bulbs, New reflectors direct 58% more light down onto plants for healthier growth and less glare. **Base unit only, top and bottom shelf, does not include add on third shelf and legs as shown, sold separately**