Features: 1 1/4Inch Spacing Between Main Circuit Breaker and Generator Circuit Breaker，Before buying, you need to make sure the model and spacing is correct. Easy to connect the generator to electrical panel and ensures main breaker can never on while the generator breaker is on. This kits avoids the inconveniences that unexpected power outages can cause. It is used to direct generator power to any circuit within your home safely. It is truly a great way to safely connect up a generator while assuring that you have access to all of your home electrical appliances. Installation Note: Before installing the interlocking kit, Attach the screws to the interlock kit first. Let simulate the use of test, so that we can better aligns the installation position, to avoid errors in the installation position, resulting in failure to use. Specifications: Materials: Stainless steel Packaging size: about 20.9x12.7x1.1cm/8.23x5x0.43inch Package Includes: 1set Generator Interlock Kits note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.