Dome Fiber Optic Splice Closure

A dome fiber optic splice closure (also called a dome enclosure, dome joint box, or vertical splice closure) is a protective outdoor housing for fiber fusion splices at network junction points. It typically has a dome-shaped top with all cable ports on one end - the "butt" configuration - making it ideal for branch and trunk connection topologies.

Dome closures (like GL-5601):​ All cable ports are on one end. Best for butt-splice topologies where a feeder cable enters and branch cables exit from the same side. Compact footprint - fits smaller handholes and pedestals. Standard choice for FTTH distribution nodes.
Inline / horizontal closures:​ Cable ports at both ends. Designed for mid-span splicing on long straight cable runs where cables enter from opposite sides. Common in backbone trunk routes and submarine cable maintenance points.
The rule of thumb: if you're branching off a distribution cable at a tap point, use dome. If you're splicing a cable break or extending a route mid-span, use inline.

IP68 is the highest standard ingress protection rating. The "6" means complete dust-tight protection; the "8" means the closure can withstand continuous immersion in water beyond 1 meter depth for a specified period - in GL-5601's case, tested per manufacturer specification.
In practice, IP68 means the closure is suitable for: underground handhole installations subject to seasonal flooding, direct burial in areas with high water tables, and manhole vault deployments where standing water is common. The silicone sealing system in GL-5601 maintains this rating across multiple re-entry cycles - unlike butyl mastic, which can degrade after two or three re-openings.

The GL-5601 supports up to 144 single fibers​ (using 6 trays × 24 fibers per tray) or 432 ribbon fibers​ (using 6 trays × 72 fibers per tray). A single integrated PLC splitter slot is also included.
Common deployment configurations: 24F, 48F, 72F, 96F, 120F, and 144F. For larger capacities (up to 288F single or 576F ribbon), we offer the GL-5601-L extended model - ask about this in your inquiry.

Yes. The GL-5601 is rated for direct burial, underground duct, aerial, pole-mount, and wall-mount installations using the same hardware - you don't need a separate SKU for different laying methods. The IP68 waterproof silicone seal handles the moisture exposure typical of direct burial environments. The high-strength PC shell resists compression loads and soil contact.
Note: For direct burial, we recommend an additional UV-stable warning tape at the burial depth and ensuring the cable strain-relief clamps are properly torqued before backfilling - vibration during compaction can loosen mechanical compression fittings if not torqued correctly.

Mechanical seal (GL-5601 type):​ Uses silicone gaskets compressed by the closure hoop. Re-enterable without tools or heating equipment. Seal can be inspected and reused. Best for locations where future re-entry for fiber additions or maintenance is expected - most FTTH and access network deployments.
Heat shrink seal:​ A heat-shrink sleeve bonds the closure to the cable jackets permanently. Provides excellent initial seal but is destructive to re-enter - the sleeve must be cut and replaced. Best for very high-permanence applications (submarine, long-haul backbone) where re-entry is rare and maximum initial seal integrity is the priority.
We manufacture both types. The GL-5601 uses mechanical seal; heat-shrink variants are available in the GL-5602 series.

Yes. The 8# splice tray configuration supports ribbon fiber up to 72 cores per tray, for a maximum total of 432 ribbon-fiber cores in a fully loaded GL-5601. Both 7# (single fiber) and 8# (ribbon fiber) trays can coexist within the same closure - useful when you're managing a mix of legacy single-fiber routes and newer ribbon-fiber cables at the same distribution node.

The cable ports accept cables with outer jacket diameters of Φ8 mm to Φ18 mm. This covers the most common FTTH distribution cable sizes (8–12mm), aerial self-supporting cables, and standard loose-tube backbone cables. For cables outside this range - flat drop cables, armoured cables, or very large trunk cables over 20mm - custom port kits are available; include the cable spec in your inquiry.

Standard MOQ is 50 units​ for production orders. Free samples are available for evaluation - typically 1–2 units shipped within 3–5 business days. Production lead time is 10 working days for standard configuration; custom OEM/ODM orders may require additional tooling lead time. Contact us with your project spec and we'll confirm availability and lead time directly.