The converter is a ring with a Ø24.8mm inner pocket and a 3mm reinforced 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 textured top surface matches the OBS bases so the converter and base look like a single piece. The Ø24.8mm inner pocket grips the 25mm base bevel in a friction fit — snug, not loose.

At ~3mm, this converter has the thickest wall in the round converter range — twice the wall of the 25→28mm. The larger size step (7mm) needs the extra material for rigidity. The textured lip gives the converter enough surface to accept basing materials — you can extend your ground texture over the lip for a seamless integrated look. The Ø22mm underside opening is smaller than the pocket, so the base is mechanically retained — it cannot fall through even without adhesive.

Designed for OBS 25mm round bases. Drop in your based model — the converter presents a 32mm round footprint. This is the single most common base upgrade path in modern tabletop wargaming: entire armies of infantry-scale models moving from 25mm to 32mm. No need to strip, rebase, or risk damaging painted collections that took months to finish.

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 banners. The underside opening is deliberately smaller than the pocket so the base can't fall through during play.

The 3mm lip is wide enough to extend your basing texture across for a fully integrated look — sand, flock, or texture paste right over the lip edge. Alternatively, paint the converter rim to match your base rim and the ring disappears at table distance. For large army conversions, batch-paint all converters at once for consistency.

Converting a full army? Line up your converters, push bases in one at a time, then batch-paint the rims. A 100-model infantry army takes about 20 minutes to convert — versus days of rebasing. If you're texturing the lips, do them all before inserting bases so the basing material doesn't interfere with the fit.

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.