3M™ Butt Connector, Heat Shrink Seamless 16-14 AWG, 94857, MH14BC. 3M™ Scotchlok™ Heat Shrink Butt Connector ensures an ideal fit with great performance. It withstands a maximum temperature of 221 degrees F (105 degrees C). Electrolytic copper construction offers good conductivity and a tin-plated finish resists corrosion.