PREMIUM SOLDER SEAL RING: Plustool solder seal wire connectors are composed of high-purity and thick solder rings; The enough solder around the wire, melt and flow until form seal on the wire. Shrinking ratio: 2:1; Tubing reduces in size and solder will melt and flow through the stripped wires, ensure strong holding, your wire will never slip out of the connector EASY TO USE: With a heat gun only, in one step create a compact, secure, waterproof and insulated connection, much faster and easier than the old way; Besides, transparent sleeve provides precise inspection when strip and insert wires inside WATERPROOF AND INSULATION: Enough hot melt adhesive to create a good waterproof seal; The melted solder ring wraps the wire to prevent metal exposure. Dual-walled design Polyolefin tubing outside provides insulation and improves pullout strength; There are two hot melt waterproof adhesive rings in each butt connector, which help it hold up better to moisture IMPROVED TECHNOLOGY: Lower temperature solder will melt faster and prevent burns in the insulation tubing; Butt connectors fetures exclusive material to avoid shrink tubing melting before solder ring; For best results, apply heat with a heat gun while continuously rotating a connector; This technique ensures even heat distribution; Besides, it can be bent after connection and no need to crimp or solder in the confined area GREAT VALUE: The package includes 800PCS Green Solder Seal Wire Connectors; It allows for factories, enterprises, schools, or stores where butt terminal are used frequently; You deserve it