Trying to find difference in lionel 6-82746 and 6-82958 I can see color
anything else. If i'm in wrong forum i'm new sorry. I want to buy Christmas
LED floodlight I can see one is newer but not sure if better.
thanks
Original Post
Looks like the first one is wired like the older accessories, has a couple of screw terminals to connect power. The second looks like it's 'plug & play'. Plug & play has a special wire connector on the end that connects to a special Fastrack section for power.
I don't have fastrack, but I did get one of the plug & play items recently (all they had) and had to either cut the plug off or buy an adapter cable for like $8-$10 (or close to it). I got out the trusty old wire nippers and went from there.
Not criticizing, but the 'HI-RAIL, O27 AND TRADITIONAL 3-RAIL O GAUGE' or 'ELECTRICAL' forums might have been better choices. 
