About this item PROFESSIONAL SURGE PROTECTION: This device can save your time and money by protecting your appliances in RV or home from high and low voltage, spike, instant surge, power failure, voltage fluctuation, brownout and load shedding, prolong the lifespan of your refrigerator. Saving you a ton of repair costs NEWLY UPGRADED PROTECTION FUNCTION: We've added a buzzer alarm that triggers when the voltage or frequency falls outside the standard range. The corresponding indicator light flashes and an alarm sounds, cutting off the power supply to the device automatically. The device won't turn back on until 30 seconds after the power supply environment returns to normal DOUBLE OUTLETS:Our surge protector can protect two appliances simultaneously. Additionally, our product features a new power grid frequency detection (HZ) function that prevents damage caused by excessive generator load on connected appliances, providing effective protection for your equipment DELAY FUNCTION: After the voltage fluctuates, once the power returns to normal, only 30s time delay to confirm that the voltage is stable and can be auto reconnected. This ensures that the appliance will not switched on-off repeatedly during fluctuations, nor will it be affected by a mive surge when power returns after a blackout SUPER EASY TO USE: Plug-and-play design. The installation is extremely flexible. The 90 plug does not occupy the space nor affect the use of other sockets. It is an ideal choice for household appliances and RV appliances