Lucky Line Products Quick Release Key Chain, 1 Pack (70701)

Brass 5-pack shows one item. Does it come with 1 or 5?

Is the body steel or nickel plated brass? Image states steel but description states brass.

The end of the part that separates, on the inside of the ring, is rounded in two pics and flat in 2 others. So what am I buying? Don't know.

Is this secure? How easily can it be accidentally released?