diff --git a/pioreactor/cli/calibrations.py b/pioreactor/cli/calibrations.py
index c5ba8007..e8fc87a6 100644
--- a/pioreactor/cli/calibrations.py
+++ b/pioreactor/cli/calibrations.py
@@ -98,7 +98,7 @@ def run_calibration(ctx, device: str, protocol_name: str | None, y: bool) -> Non
     assistant = calibration_protocols.get((device, protocol_name))
     if assistant is None:
         click.echo(
-            f"No protocols found for calibration device '{device}'. Available {device} protocols: {list(c[1] for c in calibration_protocols.keys() if c[0] == device)}"
+            f"No protocols found for device '{device}'. Available {device} protocols: {list(c[1] for c in calibration_protocols.keys() if c[0] == device)}"
         )
         raise click.Abort()
 
@@ -113,10 +113,10 @@ def run_calibration(ctx, device: str, protocol_name: str | None, y: bool) -> Non
 
     if not y:
         if click.confirm(
-            f"Do you want to set this calibration as the Active Calibration for {device}?", default=True
+            f"Do you want to set this calibration as the active calibration for {device}?", default=True
         ):
             calibration_struct.set_as_active_calibration_for_device(device)
-            click.echo(f"Set{calibration_struct.calibration_name} as the active calibration for {device}.")
+            click.echo(f"Set {calibration_struct.calibration_name} as the active calibration for {device}.")
         else:
             click.echo(
                 f"Okay. You can use 'pio calibration set-active --device {device} --name {calibration_struct.calibration_name}' to set this calibration as the active one."
@@ -127,6 +127,12 @@ def run_calibration(ctx, device: str, protocol_name: str | None, y: bool) -> Non
     )
 
 
+@calibration.command(name="protocols")
+def list_protocols() -> None:
+    for device, protocol in calibration_protocols.keys():
+        click.echo(f"{device}: {protocol}")
+
+
 @calibration.command(name="display")
 @click.option("--device", required=True, help="Calibration device.")
 @click.option("--name", "calibration_name", required=True, help="Name of calibration to display.")
diff --git a/pioreactor/tests/test_calibrations.py b/pioreactor/tests/test_calibrations.py
index 6488b32a..4b446352 100644
--- a/pioreactor/tests/test_calibrations.py
+++ b/pioreactor/tests/test_calibrations.py
@@ -10,6 +10,8 @@
 
 from pioreactor import exc
 from pioreactor.calibrations import CALIBRATION_PATH
+from pioreactor.calibrations import calibration_protocols
+from pioreactor.calibrations import CalibrationProtocol
 from pioreactor.calibrations import load_active_calibration
 from pioreactor.calibrations import load_calibration
 from pioreactor.calibrations.utils import calculate_poly_curve_of_best_fit
@@ -225,3 +227,27 @@ def test_mandys_data_for_pathological_poly() -> None:
 
     assert abs(mcal.predict(0.002) - curve_callable(0.002)) < 1e-10
     assert abs(mcal.ipredict(0.002) - 0.002) < 0.1
+
+
+def test_custom_protocol():
+    class CustomODCalibrationProtocol(CalibrationProtocol):
+        protocol_name = "custom"
+        target_device = "od"
+
+        @staticmethod
+        def run(target_device, **kwargs):
+            pass
+
+    assert calibration_protocols[("od", "custom")].__name__ == "CustomODCalibrationProtocol"
+
+    class CustomCalibrationProtocolWithList(CalibrationProtocol):
+        protocol_name = "custom"
+        target_device = ["A", "B", "C"]
+
+        @staticmethod
+        def run(target_device, **kwargs):
+            pass
+
+    assert calibration_protocols[("A", "custom")].__name__ == "CustomCalibrationProtocolWithList"
+    assert calibration_protocols[("B", "custom")].__name__ == "CustomCalibrationProtocolWithList"
+    assert calibration_protocols[("C", "custom")].__name__ == "CustomCalibrationProtocolWithList"