diff --git a/src/commands/index.js b/src/commands/index.js
index f11d74a..73b1f59 100644
--- a/src/commands/index.js
+++ b/src/commands/index.js
@@ -12,7 +12,7 @@ module.exports = [
     topic: 'data.flow',
     aliases: ['air_flow'],
     payloadSchema: { type: 'number' },
-    units: { measure: 'volumeFlowRate', default: 'm3/h' },
+    unit: 'm3/h',
     description: 'Push the measured air flow into the diffuser model.',
     handler: handlers.setFlow,
   },
@@ -27,6 +27,7 @@ module.exports = [
     topic: 'set.water-height',
     aliases: ['height_water'],
     payloadSchema: { type: 'number' },
+    unit: 'm',
     description: 'Update the water column height above the diffusers (m).',
     handler: handlers.setWaterHeight,
   },
@@ -34,6 +35,7 @@ module.exports = [
     topic: 'set.header-pressure',
     aliases: ['header_pressure'],
     payloadSchema: { type: 'number' },
+    unit: 'mbar',
     description: 'Update the header (supply) pressure feeding the diffusers (mbar).',
     handler: handlers.setHeaderPressure,
   },
diff --git a/wiki/Reference-Contracts.md b/wiki/Reference-Contracts.md
index 5bb66a0..b1315d1 100644
--- a/wiki/Reference-Contracts.md
+++ b/wiki/Reference-Contracts.md
@@ -19,8 +19,8 @@ The registry lives in `src/commands/index.js`. Each descriptor maps a canonical
 |---|---|---|---|---|
 | `data.flow` | `air_flow` | `number` | `volumeFlowRate` (default `m3/h`) | Push the measured air flow into the diffuser model. |
 | `set.density` | `density` | `number` | — | Update the air density used in OTR / SOTR calculations. |
-| `set.water-height` | `height_water` | `number` | — | Update the water column height above the diffusers (m). |
-| `set.header-pressure` | `header_pressure` | `number` | — | Update the header (supply) pressure feeding the diffusers (mbar). |
+| `set.water-height` | `height_water` | `number` | `length` (default `m`) | Update the water column height above the diffusers (m). |
+| `set.header-pressure` | `header_pressure` | `number` | `pressure` (default `mbar`) | Update the header (supply) pressure feeding the diffusers (mbar). |
 | `set.elements` | `elements` | `number` | — | Update the count of active diffuser elements. |
 | `set.alfa-factor` | `alfaFactor` | `number` | — | Update the alfa factor used in oxygen-transfer correction. |