3 pinDC powerjackpinout

If you buy less than a full reel, you'll get a single strip, but it will be a cut piece from a reel which may or may not have a connector on it. If the piece comes from the end of the reel, the connector may be on the output end of the strip!

Adafruit NeoPixel Digital RGB LED strips come to us in 4 or 5 meter reels with a 2 or 3-pin JST SM connector on each end and separated power/ground wires as shown in the picture below. If you order a full 4 or 5 meters, you get the full reel with both connectors installed.

12vdc power connector pinout

DIY? How about D-I-Wire! This barrel jack plug is great for adding a common power connector to the end of your wires. The jack is compatible with 5.5mm barrel jacks that have a 2.1mm center pole diameter. The outer shell unscrews to reveal solder terminals and a crimp strain relief. Nifty, tidy, and practical.