3M™ Scotchlok™ Butt Connector, Heat Shrink Seamless MH14BCK, 16-14 AWG, built-in wire stop for correct positioning, 250/Case. 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.