We never seem to have enough electric outlet's available when it's time to decorate the outside of the house for Christmas. A couple of years ago we found the Yellow Jacket 5-outlet outdoor adapter that gives us an extra five outlets off one extension cord. This also helps us operate a number of decorations using only one timer to turn the lights off and on. We also use this when we are doing remodeling projects and have to have several power tools plugged in at once.
The adapter is made of heavy-duty plastic that is almost indestructible. The outlets are grounded for safe operation outside. This is rated for 125 volt, 15 amps, and 1875-watt usage and will accommodate up to a 10-gauge wire. It has the UL safety rating. It has two wrap around cord lock's for secure connections preventing the cord from being accidentally pulled out of the outlet.
While this may be a little pricier than most outdoor adapters, it's durable enough to last a very long time, so it's well worth the price.