Review on 8 Pack AA Battery Holder Bundle With Wire - 1.5V, 3V, 4.5V & 6V Holders By QTEATAK by Jose Guzman

I bought a Lionel train that had quit working. The speaker wires had come loose at the coupler and shorted out the control circuit board. I needed to solder new wires on the coupler but didn't have any schematics to tell me which was the positive or negative side of the speaker. I used one of the single battery holders to use an AA battery to determine polarity and it worked great. A couple of soldered wires and a new circuit board later and I have a working Lionel train set.I only needed one battery holder but this was more economical to purchase, and I figure my son and grand-kids will find uses for the rest.