diff --git a/csaxs_bec/devices/jungfraujoch/eiger.py b/csaxs_bec/devices/jungfraujoch/eiger.py
index 27b4a050..60696b4e 100644
--- a/csaxs_bec/devices/jungfraujoch/eiger.py
+++ b/csaxs_bec/devices/jungfraujoch/eiger.py
@@ -78,6 +78,11 @@ logger = bec_logger.logger
 # the trigger period allows.
 MIN_EXP_TIME = 500e-6  # s
 EIGER_READOUT_TIME = 2e-4  # s -- matches DDG2 DEFAULT_READOUT_TIMES["ab"]
+# NOTE Each model declares its own value and passes it here; that duplication is
+# deliberate, since readout is a property of the detector (a 9M has more modules than a
+# 1.5M, and the Falcon needs 3 ms). They all happen to be 2e-4 today only because no
+# measured per-model number exists yet. This constant is the fallback for a model that
+# does not state one; deviceConfig's readout_time overrides it per deployment.
 
 
 class EigerError(Exception):
@@ -303,6 +308,10 @@ class Eiger(PSIDeviceBase):
         # self.jfj_client.connect_and_initialise(timeout=10)
 
         # Setup Detector settings, here we may also set the energy already as this might be time consuming
+        # NOTE frame_time_us is required by the API but ignored for the Eiger ("For EIGER
+        # detector this is default frame time, not used otherwise"); the exposure comes
+        # from image_time_us in DatasetSettings. The 500 is a placeholder -- it is NOT the
+        # readout time, and it is in microseconds, unlike every other time in this module.
         settings = DetectorSettings(frame_time_us=int(500), timing=DetectorTiming.TRIGGER)
         self.jfj_client.set_detector_settings(settings, timeout=5)
 
diff --git a/csaxs_bec/devices/jungfraujoch/eiger_1_5m.py b/csaxs_bec/devices/jungfraujoch/eiger_1_5m.py
index bfdb3646..92608502 100644
--- a/csaxs_bec/devices/jungfraujoch/eiger_1_5m.py
+++ b/csaxs_bec/devices/jungfraujoch/eiger_1_5m.py
@@ -11,9 +11,11 @@ from typing import TYPE_CHECKING
 
 from csaxs_bec.devices.jungfraujoch.eiger import Eiger
 
-# Gap between the end of an acquisition and the next trigger; must match the
-# delay generator's gap (DDG2 DEFAULT_READOUT_TIMES["ab"]).
-EIGER1_5M_READOUT_TIME = 2e-4  # s
+# Gap this model needs between the end of an acquisition and the next trigger. Kept
+# per model on purpose -- readout is a detector property, not a beamline constant. The
+# delay generator's gap (DDG2 DEFAULT_READOUT_TIMES["ab"]) must be at least as large as
+# the largest value among the detectors in a scan, or the slowest one overruns.
+EIGER1_5M_READOUT_TIME = 2e-4  # s -- placeholder until a measured value exists
 DETECTOR_NAME = "EIGER 1.5M"
 
 
@@ -42,12 +44,13 @@ class Eiger1_5M(Eiger):
         beam_center: tuple[float, float] = (0.0, 0.0),
         scan_info: ScanInfo = None,
         device_manager: DeviceManagerDS = None,
+        readout_time: float = EIGER1_5M_READOUT_TIME,
         **kwargs,
     ) -> None:
         super().__init__(
             name=name,
             detector_name=DETECTOR_NAME,
-            readout_time=EIGER1_5M_READOUT_TIME,
+            readout_time=readout_time,
             detector_distance=detector_distance,
             beam_center=beam_center,
             scan_info=scan_info,
diff --git a/csaxs_bec/devices/jungfraujoch/eiger_9m.py b/csaxs_bec/devices/jungfraujoch/eiger_9m.py
index bb305dd5..13f1a4c6 100644
--- a/csaxs_bec/devices/jungfraujoch/eiger_9m.py
+++ b/csaxs_bec/devices/jungfraujoch/eiger_9m.py
@@ -20,9 +20,11 @@ if TYPE_CHECKING:  # pragma no cover
     from bec_lib.devicemanager import ScanInfo
     from bec_server.device_server.device_server import DeviceManagerDS
 
-# Gap between the end of an acquisition and the next trigger; must match the
-# delay generator's gap (DDG2 DEFAULT_READOUT_TIMES["ab"]).
-EIGER9M_READOUT_TIME = 2e-4  # s
+# Gap this model needs between the end of an acquisition and the next trigger. Kept
+# per model on purpose -- readout is a detector property, not a beamline constant. The
+# delay generator's gap (DDG2 DEFAULT_READOUT_TIMES["ab"]) must be at least as large as
+# the largest value among the detectors in a scan, or the slowest one overruns.
+EIGER9M_READOUT_TIME = 2e-4  # s -- placeholder until a measured value exists
 DETECTOR_NAME = "EIGER 9M"  # "EIGER 9M""
 
 
@@ -46,12 +48,13 @@ class Eiger9M(Eiger):
         beam_center: tuple[float, float] = (0.0, 0.0),
         scan_info: ScanInfo = None,
         device_manager: DeviceManagerDS = None,
+        readout_time: float = EIGER9M_READOUT_TIME,
         **kwargs,
     ) -> None:
         super().__init__(
             name=name,
             detector_name=DETECTOR_NAME,
-            readout_time=EIGER9M_READOUT_TIME,
+            readout_time=readout_time,
             detector_distance=detector_distance,
             beam_center=beam_center,
             scan_info=scan_info,
diff --git a/tests/tests_devices/test_eiger.py b/tests/tests_devices/test_eiger.py
index c07920cd..20dcf483 100644
--- a/tests/tests_devices/test_eiger.py
+++ b/tests/tests_devices/test_eiger.py
@@ -1,4 +1,5 @@
 # pylint: skip-file
+import inspect
 import os
 import threading
 import time
@@ -23,8 +24,8 @@ from ophyd_devices.utils.psi_device_base_utils import DeviceStatus
 
 from csaxs_bec.devices.jungfraujoch.eiger import EigerError
 from csaxs_bec.devices.jungfraujoch.eiger import EIGER_READOUT_TIME, MIN_EXP_TIME
-from csaxs_bec.devices.jungfraujoch.eiger_1_5m import Eiger1_5M
-from csaxs_bec.devices.jungfraujoch.eiger_9m import Eiger9M
+from csaxs_bec.devices.jungfraujoch.eiger_1_5m import EIGER1_5M_READOUT_TIME, Eiger1_5M
+from csaxs_bec.devices.jungfraujoch.eiger_9m import EIGER9M_READOUT_TIME, Eiger9M
 
 if TYPE_CHECKING:  # pragma no cover
     from bec_lib.messages import FileMessage
@@ -537,3 +538,36 @@ def test_eiger_minimum_exposure_check_is_unchanged(eiger_1_5m):
     ):
         with pytest.raises(ValueError):
             eiger.stage()
+
+
+def test_eiger_models_may_declare_their_own_readout_time(eiger_1_5m, eiger_9m):
+    """Readout is a detector property, so each model states its own value.
+
+    They coincide today, but nothing should force them to: a 9M has more modules
+    than a 1.5M, and the Falcon needs 3 ms.
+    """
+    assert eiger_1_5m._readout_time == EIGER1_5M_READOUT_TIME
+    assert eiger_9m._readout_time == EIGER9M_READOUT_TIME
+
+
+def test_eiger_readout_time_is_overridable_per_deployment(mock_scan_info):
+    """deviceConfig's readout_time wins over the model's default."""
+    dev = Eiger1_5M(
+        name="eiger_1_5m", beam_center=(256, 256), detector_distance=100.0, readout_time=1.5e-3
+    )
+    try:
+        assert dev._readout_time == 1.5e-3
+    finally:
+        dev.destroy()
+
+
+def test_eiger_subclasses_name_readout_time_for_the_device_server():
+    """deviceConfig keys reach a device only if the class signature names them.
+
+    bec_server intersects the config keys with the named parameters of the class
+    (device_server/devices/devicemanager.py), so a subclass that only forwards
+    **kwargs silently drops readout_time -- and passing it explicitly used to raise
+    'got multiple values for keyword argument'.
+    """
+    for cls in (Eiger1_5M, Eiger9M):
+        assert "readout_time" in inspect.signature(cls).parameters