Premium Quality 2-Strand Gel Connectors are crafted from premium plastic, including a sealing gel inside the housing that promises an airtight environment for wires. Connector contacts can be crimped to prevent twisting and fraying of the strands; this is a great product at an affordable price and superior to soldering domino bricks. They can also mount cables that are difficult to solder. Gel-Filled Design - Water-resistant wire terminals are filled with gel, ensuring optimal performance against moisture and corrosion. Applicable Size - Connector terminals with contacts are suitable for wires with an inner diameter of 0.4 mm to 0.7 mm and a maximum outer diameter (including insulation layer) of 1.52 mm. Simple and Quick Installation - Wire connectors are easy and quick to install with minimal risk of moisture by simply inserting the wires into each hole and pressing the yellow button into the transparent plastic housing. Diverse Applications - Signal transmission contacts are ideal for phone cables, alarm cables, 12V cables, speaker cables, and other similar cables. Contacts can also be used for garden, invisible dog fence, underground installation, and much more.