SWING EXTENSION and L 104 NEST: Small Pet Cage Upgrade
By Ferplast U.K. | Published: 2026-11-03
Category: How-to Guides
Fit the SWING EXTENSION tunnel on thick doors for Swing 1, 3 or 5 flaps, then place the L 104 NEST in a compatible rat cage. Steps and checkpoints included.
Quick answer
Upgrade a small pet cage by fitting the SWING EXTENSION tunnel to your Swing 1, 3 or 5 flap when the mounting surface is thick, then position the L 104 NEST inside the cage as a sheltered sleeping area. Work through the steps below in order and check each point before moving on.
Why these two accessories work together
The SWING EXTENSION is a modular tunnel that adds depth to smaller Swing flaps, so the flap can sit correctly on a thick wall, door or panel. The L 104 NEST is a separate shelter that fits inside compatible rat cages and comes with a metal ladder. Used together, they solve two different problems: getting the flap to mount cleanly and giving the pet a defined sleeping corner.
When the SWING EXTENSION is the right choice—and when it is not
The extension is intended for smaller models only: Swing 1, 3 and 5. Larger Swing models already include a tunnel with the flap, so buying an extension for them is unnecessary. The extension is also not a complete fitting kit because screws are not included; you will need to supply suitable fixings for your wall or door material. If your mounting surface is thin, the standard flap may fit without the extension, so measure first rather than assuming you need extra depth.
Placement limits for the L 104 NEST
The L 104 NEST is described as an ideal shelter for rats and is designed to be added to special cages such as Jenny Kd or Ratatout. It is not a universal nest for every small pet or every cage. Check that your cage is one of the compatible models before buying, and plan the nest position so the metal ladder has clear space and does not block the cage door or wheel. The catalog does not list exact dimensions, so if space is tight, measure your cage interior and compare it with the nest before ordering.
Step-by-step upgrade
- Check your flap model and mounting thickness: Confirm that your flap is a Swing 1, 3 or 5. Measure the thickness of the wall, door or panel where the flap will sit. If the standard tunnel is too short for that thickness, the SWING EXTENSION is the part you need. Do not order the extension for larger Swing models; their tunnel is already supplied with the flap.
- Gather fixings before you start: The SWING EXTENSION does not include screws. Select screws or fixings that suit your mounting material and the flap's fixing points. Have them ready before you remove the existing flap. Using the wrong fixing type can damage the mounting surface or leave the flap loose.
- Fit the SWING EXTENSION to the flap: Attach the extension tunnel to the flap according to the flap's instructions, making sure the tunnel sections join squarely. The extension is available in two colours that work with all Swing 1, 3 and 5 flaps, so match the colour to your existing flap if that matters to you. Check that the tunnel is fully seated before tightening any fixings; a partly engaged tunnel can let draughts or water through.
- Mount the flap and test the swing: Secure the flap with your chosen fixings and open and close it several times. The flap should move freely without catching on the extension. If it binds, loosen the fixings slightly, adjust the alignment and retighten. A flap that does not swing freely may not close properly, so fix alignment before the pet uses it.
- Place the L 104 NEST inside the cage: Put the nest in a quiet corner of the cage, keeping the metal ladder clear of the door and any wheel. Add sawdust or suitable bedding inside the nest to make it comfortable. Check that the nest does not obstruct your pet's movement around the cage. Avoid placing the nest directly under a water bottle or in a draught; damp bedding defeats the purpose of a shelter.
- Introduce your pet and observe: Let your rat explore the nest and the flap area without forcing interaction. Watch for signs of hesitation or chewing at the extension. If your pet ignores the nest, try adding a small amount of familiar bedding to encourage use. Give your pet a few days to adjust; if it avoids the nest entirely, reposition it and check for draughts or blocked escape routes.
Product facts
- L 104 NEST: The L 104 NEST is a shelter for rats that can be added to special cages such as Jenny Kd or Ratatout and comes with a metal ladder. If you keep rats in one of those cages, the nest gives you a ready-made sleeping area without improvising a shelter.
L 104 NEST - SWING EXTENSION: The SWING EXTENSION is a modular tunnel for smaller Swing models (1, 3 and 5) and is ordered separately; screws are not included. You can add depth for thick mounting surfaces, but you must plan your own fixings and confirm your flap model before fitting.
SWING EXTENSION
