What chassis battery cutoff switch do you like?

I've used the Hella Keyed switch

(Hella)

on about 5 or 6 vehicles including boat/classic car/RV. Never had a
problem. I like the removable key as it makes for a great anti-theft
device and make it easy to disconnect the electrics when working on
the electrical system.

You can wire in a 10A fues across the terminals if your vehicle needs
a constant source of power to keep the clock/radio presets.