Tesla MCI-1 (Rapid Shutdown) Tesla Mid Circuit Interrupter (P/N MCI-1) for PV Rapid Shutdown with Tesla Solar Inverter, Powerwall+, and Powerwall III. Fewer MLPE required with MCI-1 than MCI-2 due to higher disconnect voltage rating of 600 V DC against 165 V DC. For solar installations with IronRidge, reference UL 3741 PV Hazard Control Installation Addendum. 20% RESTOCKING FEES AND SHIPPING WILL BE CHARGED. IF ITEM IS FUNTIONAL OR INCOMPLETE. An Important Message Regarding USPS Tracking Numbers Due to high volume of shipments sent through USPS, Tracking numbers get recycled on occasion. This means, when you receive the notificaiton that your package has been shipped via USPS, and you try to track the status of the package, it may show your package was Delivered even though the label was just generated. Please don't panic, the solution to this issue is to wait until the Post Office scans the label, then the tracking information will update accordingly. Please let us know if you have any questions. Your feedback is extremely important to us! If you are satisfied with our service please take the time to give us positive feedback. We tremendously appreciate it! We strive for your complete satisfaction. Likewise, if you have any issues, please contact us first, and we promise we will do our best to satisfy your needs and solve the problem. If we resolve your problem, we kindly ask you to still leave us positive feedback. Your kindness will be extremely appreciated!