The Festool 204871 Mounting Rails for Systainer3 M and Systainer3 L, 4-Pack is a set of rack rails designed to mount compatible Festool storage cases into a custom organization system. This is a Systainer mounting rail kit designed for workshop storage and mobile organization. If you are building out a van, shop wall, cabinet, or rolling workstation around Festool cases, this is the hardware that lets the system work the way it should. Model Number: 204871.

What matters here is not just that these are rails, but that they are made specifically for Systainer3 footprint M and L cases. Festool designed them to take advantage of the integrated rail slot on the Systainer itself, which means you are not improvising with generic brackets or shelf lips. The result is a cleaner fit, better support, and a storage setup that feels like part of the system instead of an afterthought.

The main benefit is flexibility. These rails let you create a DIY racking setup around the cases you already own, so you can organize tools, accessories, and consumables by task, trade, or workflow. For a shop, that means less time hunting for gear. For a service vehicle or trailer, it means a more secure and repeatable way to store cases where space matters and loose stacks are a problem.

Installation is straightforward. Festool calls out the rails as easy to use and easy to install, and they mount with screws, which are not included. That is worth noting because it gives you freedom to choose the right fastener for plywood, sheet goods, cabinet walls, or other mounting surfaces. Two rails are required per Systainer, so the included four-pack is enough to support two compatible cases.

From a build and layout standpoint, the dimensions matter. Each rail setup is compact enough to integrate into tight storage layouts while still supporting up to 44 pounds of load. That makes these rails a practical choice for loaded Systainers holding hand tools, fasteners, accessories, and many common jobsite essentials. They are a storage accessory, but they solve a real workflow problem by turning stacked cases into a more organized, easier-to-access system.

Compatibility is where you need to pay attention. These rails are compatible with Systainer3 M and Systainer3 L and are suitable for the SYS-RB roll board. They are not suitable for Systainer3 XXL, Systainer Combi 2 and 3, or SORTAINER units. If your setup uses those larger or different case styles, these are not the right rails. If your setup is built around Systainer3 M and L, though, this is the clean way to rack them.

This Festool storage accessory makes the most sense for cabinet installers, trim carpenters, remodelers, mobile service pros, and serious DIY users who already work inside the Systainer platform. If you are trying to get your cases off the floor, into a vehicle, onto a cart, or built into a permanent shop storage wall, these rails do exactly that without adding complexity you do not need.

Festool 204871 Mounting Rails for Systainer3 M and Systainer3 L keep the system organized instead of stacked

This is the kind of Festool accessory that makes a bigger difference in daily workflow than it looks like on paper.

• Who it's for: Pros and serious DIY users already invested in Systainer3 M or L cases who want cleaner shop storage or a more secure mobile setup.
• Why it stands out: It is purpose-built for the Systainer3 rail slot, supports custom racking, and gives you a cleaner answer than generic shelves or brackets.
• Worth knowing: This pack includes four rails, and you need two per Systainer. Screws are not included, so plan your mounting hardware around the surface you are fastening into.

• What Systainers do these rails fit? They are compatible with Festool Systainer3 M and Systainer3 L.
• How many rails are needed for one Systainer? Two rails are required per Systainer.
• Are mounting screws included? No. Festool states that screws are not supplied.
• Can these rails be used with Systainer3 XXL or SORTAINER units? No. Festool lists them as not suitable for Systainer3 XXL, Systainer Combi 2 and 3, or SORTAINER.
• What is the load rating? The listed maximum load is 44 lbs.