Descriptions : 

20pc Insulated Straight Wire Butt Connector Electrical Crimp Terminal

100% brand new and high quality.
Standard crimp and then seal heat shrink butt connectors.
Guaranteed to hold the strong crimps.

Dual-walled design, polyolefin tubing in outside and hot melt adhesive in inside
Allows visual inspection, prevents corrosion, and provided a waterproof seal
For best results use a hot air gun (You can also find it in our TOOLS category) until it reduces in size and the adhesive flows, filling gaps within the terminal

Specification : 

Color : Yellow
Suits cable\/ wire sizes : 4.0-6.0mm2

Package included : 

20 x Heat Shrink Butt Connectors

Details pictures :