Top Quality Copper Core - 350pcs butt connector kit, each connector is made of high-quality tinned copper tube, which ensures a firm connection, prevents short circuits, and not loosen after long-term use. High water resistance of IP67, can be used for marine-level line equipment, resisting severe weather Waterproof & Seamless Solder - These butt connectors are made from polyolefin, feature a dual wall design, with a shrinkable outer layer and an inner which melt into place when heat is applied to create a strong, watertight seal. Widely used in large wire connection and marine grade connection & Long-lasting - Each wire connector with a thick tinned copper that resists to hold the wire tight when crimped, to a strong connection and brave all harsh climatic conditions and your wire never slip out of the connector Visual Wiring - Translucent polyolefin tubing allows direct visual inspection of wire connections. The cable size is printed on each terminal, AWG 26-10, in eye-catching 3 colors for easy marking or identification of wire conditions Easy to Use - This crimp heat shrink butt connectors is very easy to use. , use crimping pliers to put the connector and wire into the slot for crimping, then use a heat to heat the tube so that the inner adhesive melting until it wraps the wire tightly wire connector kits are widely used in connection of holiday lights, boats, planes, trucks, , RVs, motorcycle, fish finders and other wiring projects. Applicable to industrial electrical equipment, car/truck wire connect, boat or aerospace line equipment Note: due to different production batches, the plastic box style is random,don't accept the specified packing list:350pcs Heat Shrink Butt Connectors (Yellow x 32pc, Blue x 100pc, White x 68pc, 150pc) Colour:P Color Material:PVC Package Contents: 350 x Heat Shrink Butt Connectors Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.