DURABILITY: Seamless copper barrel design provides high tensile strength and extreme stretch and mechanical damage resistance, translucent heat shrink tubing eliminates the issue of the barrel opening, high elasticity keeps steady performance HIGH QUALITY: Thick barrel ensures strong secure crimping every time to prevent wire failure, increase current flow, decrease voltage drop, and reduce equipment downtime. Your wire will never slip out of the connector WATERPROOF: Dual-walled insulation design provides waterproof adhesive seal. Designed with polyolefin outside and hot melt inside,when heat is applied, polyolefin tubing reduces in size and adhesive flows inside the insulation, provides excellent waterproof property EASY TO IDENTIFY: Easier to choose the correct heat shrink connector, different color coded tubing with wire gauge imprint provides easy identification. Blue 16 - 14 AWG(300PCS) , all heat shrink butt connectors packed in a plastic container for easy organization and storage GUARANTEED: Comply with all relevant standards, Shrinking ratio: 3:1 Camtek 300pcs Heat Shrink Butt Connectors 16-14AWG Blue