All are exploring instruments for a root canal except:
The DG-16 endodontic explorer is used to identify canal orifices and to determine canal angulation.
The CK-17 endodontic explorer serves the same purpose, but it's thinner, stiffer tip can be useful for identifying calcified canals.
Micro JW-17 - Thin Canal Explorer, Double-Ended, Single instrument.

JK-17  - Dental explorer or sickle probe.
DG-16
JK-17
CK-17
JW-17