It belongs to UR type wire conductors butt splice, which changed complicated traditional cable wire twist and soldering connection method.Insert three conductors separately into three ports without stripping conductors insulation; Crimp or squeeze the yellow button onto the inside three conductors with a pliers (here is not included.); Now you finished it!Gel-filled inside design promises an air-tight environment for conductors.Good quality and exquisitely design offer corrosion-resistant function to protect the connection against air and moisture.Product Name : UR ConnectorModel : K3Type : 3 Port, Single Blade;Applicability : To Connect two Telephone Wires, Data Signal Cables, and Other Conductors.Suitable Wire Conductor Diameter : 0.4mm-0.9mmMaterial : Plastic Casing, Gel-Filled InsideMain Color : Clear, RedSize (Each One) : 19 x 12 x 8.4mm / 0.7" x 0.5" x 0.33" (L*W*H)Total Weight : 53gPackage Content : 55 x UR Butt Splice ConnectorNote: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 +/-1-3 cm.