The converter is a ring with a Ø25mm inner pocket and a ~1.5mm wall. Push your 25mm base in from the top — the pocket grips the base bevel in a snug friction fit. The underside opening is smaller (Ø22mm), so the base physically cannot fall through — it locks in place. No glue, no magnets, no modification to your model.

To remove, push a finger through the Ø22mm underside opening and press the base out from below. You never need to grip the model, so there's no risk of damaging paintwork or fragile parts. The smaller underside opening is a deliberate retention feature, not a manufacturing limitation.

Injection-moulded from ABS plastic — same material, same tooling quality as our base range. The Ø25mm inner pocket grips the 25mm base bevel in a friction fit — snug, not loose. The Ø22mm underside opening is smaller than the pocket, so the base is mechanically retained — it cannot fall through even without adhesive.

Every converter in the OBS range is designed in-house using industry-standard CAD. The pocket dimensions are engineered specifically for OBS 25mm round bases. The ~1.5mm wall keeps the converter compact while maintaining structural rigidity.

Designed for OBS 25mm round bases. Drop in your based model — the converter presents a 28mm round footprint for systems that use 28mm or 28.5mm as their infantry base size. No need to strip, rebase, or risk damaging painted models. The converted model sits at the correct height and footprint for gaming.

The converter works with third-party 25mm round bases too, though fit may vary slightly depending on the manufacturer's outer diameter. Designed and tested for the tightest fit with OBS bases.

Part of the Open Basing System (OBS)

One Ecosystem · Every Size · Every Shape

OBS is a modular basing ecosystem designed as a whole — not a random collection of bestsellers. Every size, shape, converter, and tray is planned to work together. Independent and gamer-built.

New products added regularly — the OBS range is always growing.

Push the 25mm base into the converter ring from above. The inner pocket grips the bevel of the base and holds it firm. If the fit is very tight, press down evenly on the base edges — don't push on the model. Once seated, the top edges sit flush for a seamless appearance.

Flip the converter over and push a finger through the Ø22mm underside opening to press the base out from below. You never need to grip the model — protecting paintwork, fragile weapons, and antennas. The underside opening is deliberately smaller than the pocket so the base can't fall through during play.

Paint the converter rim to match your base rim — a single colour across both gives a seamless look at table distance. The ring profile disappears visually when the colours match. For scenic bases, extend the ground texture onto the converter lip for a fully integrated appearance.

The friction fit plus the retention lip means the base is secure for gaming without adhesive. If you want permanent, a thin ring of superglue inside the pocket before inserting makes it solid. Most hobbyists leave them friction-fit so they can switch back if base sizing changes again — that flexibility is the whole point of a converter.