The ATF-11 is a DC bar-to-bar accessory to the All-Test Pro. It conveniently makes the connection from the two All-Test Pro leads to any commutator, so one hand is still free to operate the All-Test Pro. The span is easily adjustable by a simple ccw twist of the handle. The brass contacts of the ATF-11 insure a positive connection with the commutator bars, and the ATF-11 may be used on armatures of any style or design.

The adjustable span can be shortened to contact two adjacent bars, or expanded to test 10 to 20 bars. With this positive connection to the armature, the All-Test Pro can then be used to test the windings for internal shorts, reversed connections, or partial grounds.