# Do predicate devices share every indication?

> A predicate supports the subject device’s substantial-equivalence submission, while the subject retains its own indications and restrictions.

Thermage FLX and Volnewmer illustrate why a technical comparison and an indications enclosure must be read separately. The presence of a shared predicate does not create a clinical ranking or Korean permit.

Written by the Monun Device Research Group editorial team on October 25, 2026. Canonical address: https://kliftingdevices.site/articles/predicate-limits.

## Which device is the subject of a clearance letter?

The subject is the device named in that submission and linked to its own indications enclosure.

A comparison table also names other devices, but those names play different roles. Keeping the subject and predicate in separate fields prevents a reader from attributing every comparison-row feature to the submitted product. The enclosure remains the direct source for the subject’s US use summary.

**Roles inside a device submission**

| Role | What it identifies | Reading boundary |
| --- | --- | --- |
| Subject device | Device under the submission | Its own indications enclosure |
| Predicate device | Comparison used for equivalence | Do not inherit all its uses |
| Technical comparison | Specified characteristics | Not a clinical superiority trial |
| Applicant summary | Submitted technical account | Separate from FDA-authored letter |

## Why keep Thermage FLX indications with FLX?

The FLX document separates RF-only and RF-with-vibration indications for that named system.

Another device may compare selected technical properties with FLX while retaining a different indication. Reading the FLX wrinkle wording into that device would skip the submitted enclosure. Mode-specific language matters even within FLX, so it cannot be transferred by brand familiarity.

## What is read from the Volnewmer enclosure?

The selected Volnewmer document states dermatologic electrocoagulation and hemostasis of soft tissue.

The regulatory summary follows the device’s own statement. A manufacturer page may use different promotional language, which is retained as the manufacturer’s role rather than silently replacing the enclosure. This separates product retrieval from a claim about regulatory scope.

**Two document-specific indication examples**

| Device source | Recorded example | Avoided transfer |
| --- | --- | --- |
| Thermage FLX | RF-only / RF-with-vibration scope | All FLX uses to another RF device |
| Volnewmer | Soft-tissue electrocoagulation/hemostasis | FLX wrinkle wording by predicate relationship |
| Oligio X | Non-invasive electrocoagulation/hemostasis | Blanket lifting approval |
| All three | US document scope | Current Korean authorization |

## Does substantial equivalence mean equal clinical outcomes?

The regulatory decision and a comparative clinical outcome are different kinds of evidence.

The source relationship may compare intended use and technical characteristics for the submission. A lifting, pain or safety comparison needs its own matched clinical design and endpoints. A predicate name alone cannot supply that study or the missing patient-level denominator.

## Does a shared regulatory class erase scope differences?

A shared class or product category does not replace each device’s own restrictions and enclosure.

Technical families can include different applicators, modes and subject records. A category label is useful for retrieval, while a use claim requires the exact device and event. Combining the two fields would make a narrow regulatory statement look like a universal indication for the whole family.

## Can predicate reasoning establish a Korean permit?

The US predicate relationship does not match the current Korean legal model, accessory or permit.

The domestic permit field remains unresolved in the initial research. It requires a local label and current permit record rather than a chain of US comparisons. Even a direct US event for the exact trade name retains its own jurisdiction and cannot fill the Korean field.

## What is a useful predicate comparison checklist?

Identify the subject, predicate, characteristic being compared and subject indication before reading a claim.

The claim checker keeps these fields visible through pre-edited examples. It does not generate legal conclusions from an arbitrary advertisement. When the stated use or accessory is missing, the missing field is the result rather than an assumed match based on a nearby brand name.

## What else do people ask about Predicate device limits?

### Does the word predicate mean a new device has every older use?

The subject device retains its own indications enclosure.

### Is a technical comparison a patient trial?

Its source role is a technical comparison; a clinical result needs its own study.

### Can FLX wrinkle indications be copied to Volnewmer?

The Volnewmer regulatory summary follows its own enclosure.

### Does a shared class prove equal safety?

The class does not provide a comparative safety denominator.

### Does a predicate chain confirm Korean use?

Current Korean labels and permit records need separate matching.

## What should you read next?

- [What does FDA clearance mean for a lifting device?](https://kliftingdevices.site/articles/clearance-and-approval)
- [How is a Korean device permit matched to a model?](https://kliftingdevices.site/articles/korean-permit-matching)
- [Korea lifting model lookup](https://kliftingdevices.site/tools/model-finder)
- [Korea device indication checks](https://kliftingdevices.site/tools/claim-checker)

## Where do these numbers come from?

- [K170758 : Thermage FLX System and Accessories](https://www.accessdata.fda.gov/cdrh_docs/pdf17/K170758.pdf) - U.S. Food and Drug Administration
- [K240248 : Volnewmer](https://www.accessdata.fda.gov/cdrh_docs/pdf24/K240248.pdf) - U.S. Food and Drug Administration
- [K243929 : Oligio X](https://www.accessdata.fda.gov/cdrh_docs/pdf24/K243929.pdf) - U.S. Food and Drug Administration