The Flame King ACR-2 two-stage auto-changeover regulator connects to two propane cylinders simultaneously and automatically switches to the full tank when the primary one runs empty, with no interruption to your appliances. A visual indicator window on the regulator turns red when the primary tank is empty and the system has switched over, letting you know it is time to swap and refill that cylinder. It is the recommended regulator setup for full-time RVers or anyone who does not want to worry about running out of propane unexpectedly. The regulator is available with 12, 15, or 18-inch pigtail hoses included, or without pigtails if you already have your own.

Flame King offers several accessories for monitoring propane on tanks that do not have a built-in gauge. The Grip Propane Scale is a handheld digital scale that shows the exact weight (and therefore fuel remaining) when you lift the tank. The Smart Wireless Propane Tank Scale uses Bluetooth to connect to a smartphone app for ongoing monitoring. For an inline option, the Flame King Propane Gas Level Indicator (YSN212B) screws directly onto the tank valve, features a glow-in-the-dark dial, and includes an emergency flow shutoff. All three are compatible with standard 5 to 40 lb propane tanks.