what and where is the 2 4 5 coverage

What is this coverage and where is it I here people talking about it

Nickel 2-4-5 is a great formation that can be found in lots of playbooks.
Several that I know of:
Patriots
Steelers
Cardinals
Cowboys
Chargers

Browns got this as well.....


I like the odd split over the 2-4-5 myself so Im using the Jets book. But I might have to give 2-4-5 a try here soon. It looks like it got more plays then the odd split.