What amount reserves to keep in your rental bank accounts?

[Jonathan Farber]

Hey all, doing some financial planning this week as we are looking to add some properties. Call me old fashion, but I like the idea of having a few months PITI (Principle, interest, tax, insurance). Any good rules or thumb or recommendations from buy and hold investors on how many months reserves they like to leave per unit earmarked?

@Jay Dertzbaugh @Brad Farber @Ruben Kanya