Usage and properties: 1) The interface device used in connecting backbone cables and distributing cables 2) Realizing the obligation in node points, straight in, fiber distributing or adjusting between backbone cables and wiring cables 3) The body of the case is made of stainless steel, electrostatics plastic-spray surface, anti-corrosion, suitable for ground or aerial installation 4) The area for fixing, splicing and wiring is classified clearly and easy for installation and checking the line Environment: 1) Environmental temperature: -25°C ~ +60°C 2) Relative humidity: 3) Atmospheric pressure: 70 - 106KPa Main technical indexes: 1) Insertion loss: 1.31, 1.55um LD lamp-house, SM≤0.18dB, MM≤0.30dB 2) Return loss: 1.31, 1.55um LD lamp-house, SM PC≥45dB, UPC≥50dB, APC≥60dB 3) Insulation resistance: ≥2 x 10,000mΩ/500V DC 4) Voltage-resistance strength: non-puncture, no arc-over under 3kV DC/1min