The hand on a watch that displays the seconds is called the seconds hand. If you are referring to used watches for sale (second-hand watches), they are second-hand watches. If it's a used timepiece that displays the seconds, it is a second-hand watch with a seconds hand.
Questions and Answers About Watches
Guide To Buying Used & Vintage Watches In Tokyo, Japan
West End Watch co] [Question] seconds hand stopping at the same
The A:S Guide to High-End Dress Watches – Analog:Shift
A Guide To Wearing 2 Watches at the Same Time - Our Culture
How To Buy Pre Owned Rolex Watch: The Ultimate Guide
Do Breitling and Rolex watches retain their value over time? - Quora
The Length of the second hand ?
Used Watches Buying Guide - Microbrand Watch World
Help! Omega cal. 1342 Seconds Hand going back and forth
