Usage and properties: 1) Used for protective connection between two or more optical cables 2) Suitable for single core fiber optic cables and ribbon fiber optic cables 3) Suitable for such laying modes in fiber optical cable circuits as aerial, pipelined, and direct-buried installation Environment: 1) Environmental temperature: -40°C - +65°C 2) Atmospheric pressure: 70 - 106KPa Main technical parameters: 1) Airproof performance: airing pressure inside box of 100KPa, pointer immovability after 24 hours or no air bell within 15min when cease in the common temperature water 2) Re-encapsulation performance: no change in the index of airproof performance after three times of repeated encapsulation 3) Insulation resistance: ≥2 x 10,000mΩ 4) Voltage-resistant strength: under the effect of 15kV DC/1min, non-puncture, non arc-over