Description: 【Standard Conduit Openings】: Equipped with standard-sized conduit openings, including sleeves and plugs, ensuring compatibility with various installation needs 【Weatherproof Design】: This round power outlet box is designed to withstand the elements, making it suitable for both indoor and outdoor use in industrial-style lighting setups 【North American Compatibility】: Built to standard North American dimensions, this outlet box is compatible with all covers and plug-ins, providing versatility in your lighting projects 【Pre-threaded Knockouts】: Features pre-threaded knockouts on both sides and the back of the box, allowing for flexible installation and wiring configurations 【Compact Dimensions】: With a diameter of 101.6mm, this round power outlet box offers a compact solution for your lighting fixture installations without compromising on functionality   Specification: Material: PP Size Chart:Diameter 101.6mm/40.00inch, 1/2" Holes Package Includes: 1x Round Electrical Enclosure Box (US Standard) Note: Please allow slightly errors 1-2cm differences due to manual measurement.