21 ELECTRICAL DEVICES INTENDED FOR USE IN TELEPHONE COMMUNICATION SYSTEMS-NAMELY, SERVICE OBSERVING SYSTEMS FOR PERMITTING A PERSON TO OBSERVE THE QUALITY OF TELEPHONE SERVICE BEING PROVIDED ON ONE OR MORE TELEPHONE LINES OR TRUNKS
Trademark Events
Oct 16, 1995
Expired Sec. 9
Apr 1, 1980
Registered - Sec. 8 (6-Yr) Accepted & Sec. 15 Ack.