Nite Ize S-Biner SlideLock #4 - Stainless

i want to use this to hook two 1/2" pipe. is the opening big enough to clip to 1/2" pipe? Thanks in advance.

Is the stainless really solid stainless steel or just coated with chrome?

How does the lever spring shut when there are no springs to activate it? Does it use gravity? How does the lever spring close?

I have the stainless steel model, but can't figure out the way to attach the keys. How can I attach them?