Milton 551 Truck Inflator Regulator Review

I'm a trucker, I bought it to save time and tires. Works great but it would be better if the cartridges close automatically so the 2nd tire doesn't deflate when the 1st cartridge is removed. .I can add a check valve to any hose. The pressure gauge does not work. The regulator is cheap and the dial is starting to fail. If this product was made better, or $85.00 instead of $200, that would be a lot.