50 Amp Transfer Switch: Automatic 50 Amp Transfer Relay Switch For Rvs And Product Details ?Double Protection ? Double protection of built-in mechanical interlocks and control circuits prevents two separate 120/240 volt AC power sources from entering the AC distribution board at the same time and causing a short circuit. ?This automatic transfer switch has a 30 second selectable delay with quick-connect terminals for easy installation. ?This transfer switch has been pre-wired to automatically change the primary source of AC current from shore power to generator or inverter power when activated ?Easy-to-remove protective cover with wiring schematic inside ?1 year warranty is provided. If you have any problem , please feel free to contact us Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.