These connectors / wire are for 4 pin 5050 3528 RGB LED strips

Easy use for LED SMD 3528 / 5050 RGB Flexible Strip

LED strip light extension connector will extend the use of LED strip lights

For non-waterproof LED strip light, just slide in the ribbon and make sure positive and negative poles match

For waterproof LED strip light, peel off silicon on the surface around soldering line area and gently slide in the strip light into the connector body and you will feel the connector grab the ribbon