Bought this for my Black & Decker Mower and Black & Decker grass trimmer that I also got off of Amazon. Both do not include a power cable, so you'll need something like this.
As gauge gets smaller the cable gets bigger. So 16 gauge cable is smaller than 12 gauge. 14 is right in the middle. Bigger cables can take more power (amps). The mower is 6.5 amps and the trimmer is something less than that, so this cable is plenty for either of them (not at the same time.. although it might do that just fine, who knows.. I wouldn't try it).
Easy to tug around, fits snugly in both devices and is bright to see and easy to coil. Couldn't really ask for more.