The MK5196 continuity tester, for RJ11, RJ12 and RJ45 connectors, with ISDN and Category 6 to 8 cables named.
What the page states
The four faults it looks for are named one at a time, and the remote unit shows a light for each of the eight conductors, so a crossed pair or a broken wire can be read off directly. That is what a continuity tester is for, and the listing says it plainly.
What it leaves out
Nothing says what the tester runs on — battery type, or whether a battery is included. On the cable tester shelf, where several pages state a 9 V cell and whether it is in the box, that is the line to ask the seller about.
Against the other testers here
The NOYAFA NF-8508 on the same shelf measures cable length from 2.5 to 200 m and runs on a built-in 1,500 mAh battery charged over USB-C; the INTELLINET 780094 adds USB, FireWire and coaxial connectors. The MK5196 does neither. It is a plain two-piece continuity tester, which is what a home installer needs to check a run just terminated, and its remote unit is what lets it test cable already pulled through a wall.
