Just what is difference between c7 and c9 bulbs?
If you're standing in the holiday aisle wondering what is difference between c7 and c9 bulbs, you aren't alone. It's one of those things where they look almost identical on the shelf until you hold them side-by-side or, worse, try to screw a replacement bulb into a string that's already hanging on your gutters. I've been there, shivering on a ladder, realizing I bought the wrong size. It's a classic homeowner headache, but once you know the basics, you'll never mix them up again. ...