XLCS Designs STORMWARDEN Cage for the GoPro MISSION 1 PRO ILS Introduced – One-Piece Design, 100+ Mounting Points, Built-In ARCA Base

by Johnnie BehiriToday

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XLCS Designs has brought the STORMWARDEN to IBC 2026, a one-piece aluminum cage for the GoPro MISSION 1 PRO ILS with over 100 threaded mounting points, a built-in ARCA-Swiss base, dual cold shoes, and optional 15mm rod support. We sat down with company owner William von Tagen at the show to talk about why a cage maker known for Blackmagic and Nikon bodies decided to take GoPro’s interchangeable-lens action camera seriously.

We’ve covered XLCS Designs before, from the single-piece Full Metal Jacket cage for the Blackmagic PYXIS 6K to the Nikon ZR cage that started shipping earlier this year. The STORMWARDEN applies the same approach to a much smaller body. The cage is machined from a single piece, the camera drops in and is held by one screw from below, and the outer surfaces carry 1/4″-20 holes on a 9mm (0.35in) center-to-center grid alongside around ten 3/8″-16 threads with ARRI-style locating pins. Let’s take a closer look.

Why a cage for an action camera

William said he was excited when GoPro announced the MISSION 1 series at NAB 2026, at a point when many people were not sure what to make of the camera. His view is that most buyers will pick it up as an action camera, but that the MISSION 1 PRO ILS with its Micro Four Thirds mount can do more once it is rigged: a B camera on the day, with a better lens on the front, picking up shots the A camera cannot reach. In his description, the bare camera offers a single mounting point, and this camera in particular will end up on cars, boats and possibly aircraft, so the cage is there to give it the mounting options the body does not have.

A one-piece cage with over 100 threads

The design philosophy William described is the same one XLCS has used since it started about three years ago: a one-piece structure so the camera goes in and out quickly, and as many mounting options as the surface area allows. On a cage this small, that still means more than 100 1/4″-20 threaded holes, which William was quick to say is not an invitation to fill every one of them. The point is that every setup is different, and being able to move an accessory by half an inch or 9mm in any direction can change how a rig comes together.

Tolerances are where a one-piece design earns its price, according to William. The camera has one fixed mounting point inside the cage, and if the fit is off by a fraction of a millimeter, the camera either will not go in or sits loose. He put it in practical terms: too tight and it does not fit, too loose and there is play the moment a focus motor pushes against the lens. The cost of getting that machining right, plus the R&D behind each cage, is what he pointed to when asked about being a smaller Western manufacturer competing against a market where cages have become a race to the bottom. His argument is that a $60 accessory holding together a $2,000 camera and $3,000 of lenses is the wrong place to save money.

Built-in ARCA base and cold shoes

The STORMWARDEN is the first XLCS cage with the baseplate built into the cage itself. The Nikon ZR cage left that as an add-on, and William said customers asked for it to be integrated. On the MISSION 1 PRO ILS, the body width happened to match an ARCA-Swiss dovetail, so the cage carries a built-in ARCA base, built-in cold shoes, and the ten or so 3/8″-16 threads with locating pins for accessories that need to stay put.

Getting the camera out for a battery swap is a matter of loosening the single screw underneath, as William demonstrated at the booth. The body of the standard MISSION 1 and the MISSION 1 PRO is the same size, so the cage also fits the fixed-lens models.

Media Mod, USB-C and a breakout box in development

GoPro’s own Media Mod does not fit inside the STORMWARDEN, and William said the company has already had questions about that. XLCS is developing its own alternative in the form of a breakout box with a full-size HDMI output, a 3.5mm jack for audio or timecode in, and a USB-C port for power in or offloading media. It will mount anywhere on the rig rather than clip to the camera. In the meantime, the cage has an opening on the side for the camera’s USB-C port and an optional cable lock, so external power or monitoring does not put strain on the connector.

15mm rods via a dog bone

For lens support, a follow focus or a matte box, XLCS offers a small dog bone that bolts to the side of the cage and adds 15mm rod mounting at the standard 60mm spacing. It can be removed when not needed, and XLCS also sells the rods and additional dog bones that drop the rods further below the camera. Some of the accessories on the show rig were from other manufacturers, and William said the XLCS pieces can be added à la carte. According to the product page, an optional lens adapter support is also available to take load off the MFT mount when using heavier adapters.

The rest of the XLCS lineup

The company started with a cage for the original Blackmagic Pocket Cinema Camera, followed by the Micro Studio Camera 4K G2 and the SIGMA fp, before moving to current bodies with the PYXIS 6K and 12K cage (over 300 mounting points) and the Nikon ZR, which William said is hard to keep in stock. A cage for the Kinefinity VISTA is about to launch, and one for the Sony FX5 is in the works. At NAB, XLCS also showed its Killdozer system, which included a weather-sealed cage for the PYXIS monitor with its own mounting points. (Won one of our NAB 2026 Best of Show Awards)

Asked about a cage that would lock down the DJI Ronin 4D for use as an A camera, a request that ranked among the top answers in our recent Ronin 4D poll, William did not commit to anything but noted that users tend to rig his cages in ways they were never designed for. He gave the Micro Studio Camera G2, a studio camera with no internal recording, as an example of a body people build out far beyond its intended use.

Price and availability

The STORMWARDEN is on pre-order, with units already in production and, according to William at the show, about two to three weeks from shipping. The cage on its own starts at $189, with bundles at $204.99 for the cage plus 15mm dog bone, $209.99 with the USB-C cable lock, and $229.99 for the cage with both. For more information, please visit the XLCS Designs website.

Would you rig a MISSION 1 PRO ILS as a B camera with rods and a follow focus, or does the appeal of the camera end where the cage begins? Don’t hesitate to let us know in the comments below!