The Rowe / AMI speaker part number L-2539 is used in the following models:
JAL, JEL, JBM, JAN, JAO, MM1, MM3 and MM4.
These models also have smaller tweeter and mid-range speakers and this 12 inch is the woofer.

This is a 16 ohm voice coil speaker.
The actual weight of the speaker is 4 pounds.

The Source Date Code 137741 indicates that this is a CTS (Chicago Telephone Supply) speaker that was built during the 41st week of 1967.

The cone is original and in good condition.