Integrating the FOSCYJ4 dome closure across our urban FTTH drop deployments solved several space-constraint issues in cramped manholes and wall-mount boxes. With compact dimensions of 310 (H) × 190 (D) mm and a net weight between 1.55 kg and 1.74 kg, it is significantly easier to handle overhead or in tight quarters compared to larger 500 mm enclosures. The 4-port layout includes 1 primary 25 mm port for uncut mid-span feeder loops and 3 branch 16 mm ports for distribution drops. The heat-shrinkable sealing system and thermoplastic rubber grommets maintain a rock-solid, weather-resistant seal rated for harsh temperatures from -40°C to +65°C. Supporting up to 48 bunchy fibers or 72 ribbon fibers across 4 splice trays, it provides the ideal capacity for lower-density spur lines.
Birgit Lindqvist
2025年11月10日
At a reference baseline starting at only $19 USD, FirstFiber’s FOSCYJ4 dome closure provides remarkable value for utility-grade fiber cable management. We deployed a batch for aerial pole-mounting and wall-mounting contracts, and the included hanging hoop set made exterior installations seamless. The closure arrives as a complete turnkey kit equipped with splice trays, fiber splice protective sleeves, nylon ties, a grounding wire, abrasive cloth, an M10 wrench, and heat-protective aluminum-foil paper. We also added the optional testing valve to run air pressure checks before finalizing overhead deployments. The high-impact Polycarbonate (PC) outer body stands up extremely well to direct solar exposure and physical stress.
Javier Ruiz
2026年5月14日
We standardized on the FOSCYJ4 for branch connections in underground pipeline, duct, and direct-buried cable runs. The interior design is well thought out, featuring a maximum of 4 splice trays where each dual-layer tray neatly organizes 12 bunchy fiber splices. A dedicated fiber holding tray stores un-spliced loose tube buffer fibers cleanly without forcing tight bend radiuses. Selecting between the 12-core, 24-core, 36-core, and 48-core capacity options gave our field teams exactly the tray density needed for small distribution nodes. The heat-shrinkable seal around the cable entry ports creates an airtight barrier that resists long-term moisture ingress underground.
