【PREMIUM IN QUALITY】- Every single piece of our crimp connectors is made with tinned thick red copper barrel and polyolefin heat shrink tubing[Shrink Ratio 3:1], which ensure secure crimping and tight wire connection with high current flow and minimum voltage drop, preventing wire failures | 【SAFETY MATTERS】- Safety is the top priority during any of your work, certificated products can ensure you reassured and secure using experience. Our heat shrink connectors meet the standards of CE, RoHS, ISO9001, SGS, you’re allowed to use these proffesional butt splice connectors with full confidence for a variety of electrical projects and wire connection issues | 【MADE TO LAST】- Thanks to the thick tinned copper and seamless barrel desgin, it ensures strong and secure crimping all the time with no wire coming off issues. What's more, the polyolefin heat shrink tubing provides the high tensile strength and resistance to mechanical damage so there's no worry of rat chewing or similiar phisical damage issues. When heated with a heat gun, the adhesive melting inside create a waterproof and insulated seal, preventing electric leakage and corrosion | 【WIDE APPLICATION】- Marine grade heat shrink butt splices can be widely applied in areas such as automotive industry, marine, science projects, family electrical wire connections and so on, due to its durability, steadily, water and corrosion resistace | 【THOUGHTFUL BUTT CONNECTOR KIT】- Considerate pacakge includes 5 different sizes of butt connectors containing 30Pcs CRYSTAL[26-24 AWG], 100Pcs RED[22-16 AWG], 80Pcs BLUE[16-14 AWG], 15Pcs BLACK[14-12 AWG], 20Pcs YELLOW[12-10 AWG] in an organized case, to as possibly meet your different needs of wire gauges for electrical projects. The color and the printed wire gauges in the surface help you select needed connectors in seconds