Tiella 800RLP4C402Z Dual-Feed Low-Voltage Power Canopy is for the MonoRail system (not included). The power canopy requires 800AT600T 600W (2 by 300W) dual-feed remote transformer – not included. Mounts to a standard 4-inch square junction box with round plaster ring (provided by electrician). A compatible Rigid Standoff is 2IN (800RLS02Z), and to drop the system from the ceiling, power extenders can be used (800RLP**Z) which are available in lengths from 6IN to 96IN (both components sold separately) – Requires Two of Each Component when/if used. The 800RLP4C402Z is 4.4-Inch diameter by 1.5-Inchhigh. The 800RLP4C402Z comes one per package. Tech Lighting started small back in 1988. Since then we have continuously built our reputation for timeless design, precision engineering, and trust. Today, we are recognized as the industry leader in low-voltage lighting systems and for our expansive collection of premium light fixtures. At our core is an intense appreciation for art and science, sophistication and imagination. We race to introduce new innovations to the market - both in design and technology. We travel the globe visiting trade shows not just in our industry, but everywhere that design can be observed - from furniture to fashion. We partner with glass artisans throughout the world to create the highest quality blown glass. Though, it extends beyond glass. Every detail counts. Our passion does not end with product. We are fanatical about exceeding our customershighest expectations with short leads times, on-time delivery, expansive custom capabilities and the most knowledgeable and accessible customer service and technical support department in the industry.