Dual-walled Design:Polyolefin tubing outside and hot melt rings inside effectively improve waterproof performance and prevent wire corrosion.[Easy To Use] - Shrink Ratio 2:1. NO Crimping Needed. Transparent sleeve provides precise inspection when strip and insert wires inside. Color-coded tubing makes it easy for you to pick up for use.[Durable Connection] - 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.[Wide Applications] - perfect used for vehicle, motorcycle, boat, DIY electrical wirings and other outdoor applications. Solder Connector Kit compliants with ROHS, ISO 9001:2008, SGS and standards.solder wire connectors:Whether you are working on your boat, vehicle, home or scientific project, our heat shrink solder and seal connectors will ensure solid soldering, increased current flow and weatherproof connections every time~Shrinkage Ratio 2:1An easy One-Step Wire Connections.Easy Identification:Color coded connector tubing.Polyolefin heat shrink butt connectors improve Pullout Strength.High-quality wire connectors in Seal, Strain Relief, Cable Check and Insulation.Melted Solder ensures wires Strongly Connected and avoids wires slipping out from the terminal.colour:Yellow + blue + white + redMaterial:PEsize:6x1x1CMPackage Contents:400*solder seal wire connectors(150*Red 150*Blue 60*White 40*Yellow)Only the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.