Romex Splice In Wall

Romex Splice In Wall - I'm not sure if this can be used in a wall where it will be buried? Products like this have been around for a long time. I remember seeing romex (nm) splice. The mobile home splicer might be an option, but only if the original wiring is 1993 or later. It won't work with fat old romex or with any that has a reduced ground wire. Tyco makes a splice kit for #14 and #12 romex. I read their brochure. I'm not sure if this can be used in a wall where it will be buried?

I'm not sure if this can be used in a wall where it will be buried?