GN Netcom 1000 Remote Handset Lifter

Does this work for multiple lines? Are you able to put someone on hold without just muting them?

Will this work with a Jabra Engage 75 Stereo headset?

I have a jabra 9400bs headset and a jabra lifter that looks like this one.no gn1000 nameplate.stopped lifting,lights still work. will this work?

I have Mitel 5330e phone and Jabra 9450 will this lifter work OK with this phone and headset?