But the NTE5 belongs to OR so you arent supposed to have "a spare"!
I have kept my old one as "a spare" 
I think people are talking about the NTE5A, (which is yours), and replacements for that. The demarcation point is in reality the test socket.
The NTE5 is the bit screwed to the wall with the incoming line connected to it and including the main master circuitry. The standard faceplate with a single phone socket is an NTE5A. A faceplate with no socket, such as might be used for a master in the loft but not used - merely feeding extensions everywhere, is an NTE5B.
My broadband basic info/help site - www.robertos.me.uk
Domains,website and mail hosting - Tsohost.
Connection - Plusnet Extra Fibre (FTTC). Sync ~ 56.0/13.9Mbps @ 600m.
"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
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Allergy information: This post was manufactured in an environment where nuts are present. It may include traces of understatement, litotes and humour.