The adapters are intended to be used for calls coming into {TAIL ~ a PBX} on a DID trunk or {HEAD ~ E&M tie line} 
The adapters are intended to be used for calls coming into { TAIL ~ a PBX } on a DID trunk or { HEAD ~ E&M tie line }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD