The converter is an open-bottomed frame with a pocket sized to accept a 20mm square base. Push the base in from the top — it clicks into a snug friction fit. The top edge of the base sits flush with the top edge of the converter, giving a seamless, unified appearance. No glue, no magnets, no modification to your model.

To remove, push the base out through the open underside — you never need to grip the model itself, so there's no risk of damaging paintwork or breaking fragile parts.

Injection-moulded from ABS plastic — same material, same tooling quality as our base range. The textured surface matches the OBS bases so the converter and base look like a single piece. The tapered inner pocket grips the base securely without needing adhesive — the 20mm base pushes in and holds firm.

Every converter in the OBS range is designed in-house using industry-standard CAD. The pocket dimensions are engineered specifically for OBS 20mm square bases — a snug fit, not a loose rattle. The open underside is a deliberate design choice: push the base out from below to remove without touching the model.

Designed for OBS 20mm square bases. Drop in your based model — the converter presents a 25mm square footprint for systems that have moved from 20mm to 25mm infantry sizing. No need to strip, rebase, or risk damaging painted models. The converted model sits at the correct height and footprint for tournament and competitive play.

The converter works with third-party 20mm square bases too, though fit may vary slightly. 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 20mm base into the converter from above. It should click into a snug friction fit — the tapered pocket grips the base walls. If the fit is very tight, press down evenly on the base edges, not on the model. Once seated, the top surfaces sit flush.

Flip the converter over and push the base out from below through the open underside. This is a deliberate design feature — you never need to grip the model or pull it out from the top. This protects paintwork, fragile weapons, banners, and anything else that would break if you tried to pry the model out.

The converter texture matches OBS bases, so a single colour across the rim and bevel gives a seamless look. Paint the converter rim to match your base rim and it disappears visually — especially effective in ranked formations where consistency matters. If your existing bases have scenic rims, match the converter rim to the same scheme.

The friction fit is secure enough for gaming without adhesive. If you want a permanent bond, a thin line of superglue around the inner 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.