MEIRIYFA 4 Pole Speakon Panel Mount Socket Connector,4 Pin Audio Speakon Female Round Jack Twist Lock Adapter for NL4MP, NL4MPR, NL4FC, NL4FX, NLT4X (8PCS)

Jacks have nice brass threaded insert for screws. I didn't need them and I drilled them out for 1/8" rivets to mount them.

The metal threaded inserts are very loosely pressed into the plastic housing. It’s very easy to pull out the insert accidentally with very little pressure. Get a name brand set.

The embedded nuts have either stripped/popped out or the connectors have failed to maintain connection internally with less than 10 connector insertions. These are very poor quality connectors. Even while building the rack the back of try connectors began to come apart. If you are going to use these for anything other than a throw away installation, I suggest avoiding these.