diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6b8f0d3..ba47a80 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@ All notable changes to this project will be documented in this file.
 
 - Description: Dynamixel 2R (MJCF)
 - Description: YAM (MJCF) (thanks to @kevinzakka)
+- Description YAM (URDF)
+- Description RBY1 Mobile Manipulatior (URDF)
 
 ## [1.17.0] - 2025-05-08
 
diff --git a/README.md b/README.md
index edd3411..625573d 100644
--- a/README.md
+++ b/README.md
@@ -164,6 +164,7 @@ The DOF column denotes the number of actuated degrees of freedom.
 | `widow_mj_description`        | WidowX                | Trossen Robotics         | MJCF       | BSD-3-Clause |
 | `xarm7_mj_description`        | xArm7                 | UFACTORY                 | MJCF       | BSD-3-Clause |
 | `yam_mj_description`          | YAM                   | I2RT Robotics            | MJCF       | MIT          |
+| `yam_description`             | YAM                   | I2RT Robotics            | URDF       | MIT          |
 | `z1_description`              | Z1                    | UNITREE Robotics         | URDF       | BSD-3-Clause |
 | `z1_mj_description`           | Z1                    | UNITREE Robotics         | MJCF       | BSD-3-Clause |
 
@@ -267,6 +268,8 @@ The DOF column denotes the number of actuated degrees of freedom.
 | `sretch_mj_description`       | Stretch 2             | Hello Robot              | 14  | MJCF       |
 | `sretch_3_mj_description`     | Stretch 3             | Hello Robot              | 14  | MJCF       |
 | `tiago_description`           | TIAGo                 | PAL Robotics             | 48  | URDF       |
+| `rby1_description`            | RBY1                  | Rainbow Robotics         | 24  | URDF       |
+
 
 ### Quadrupeds
 
diff --git a/robot_descriptions/_descriptions.py b/robot_descriptions/_descriptions.py
index 9a5592d..8199367 100644
--- a/robot_descriptions/_descriptions.py
+++ b/robot_descriptions/_descriptions.py
@@ -217,6 +217,8 @@ def has_urdf(self) -> bool:
     "widow_mj_description": Description(Format.MJCF, tags={"arm"}),
     "xarm7_mj_description": Description(Format.MJCF, tags={"arm"}),
     "yam_mj_description": Description(Format.MJCF, tags={"arm"}),
+    "yam_description": Description(Format.URDF, tags={"arm"}),
+    "rby1_description": Description(Format.URDF, tags={"mobile_manipulator"}),
     "yumi_description": Description(Format.URDF, tags={"dual_arm"}),
     "z1_description": Description(Format.URDF, tags={"arm"}),
     "z1_mj_description": Description(Format.MJCF, tags={"arm"}),
diff --git a/robot_descriptions/_repositories.py b/robot_descriptions/_repositories.py
index 8349ac2..e5a57d5 100644
--- a/robot_descriptions/_repositories.py
+++ b/robot_descriptions/_repositories.py
@@ -305,4 +305,14 @@ class Repository:
         commit="9a6a057a055babaf47119fac42c361fffc189128",
         cache_path="skydio_x2_description",
     ),
+    "i2rt": Repository(
+        url="https://github.com/i2rt-robotics/i2rt.git",
+        commit="8a8f804d72b41a04a5c69520031aec9a5d328104",
+        cache_path="i2rt",
+    ),
+    "rby1_description": Repository(
+        url="https://github.com/uynitsuj/rby1_description.git",
+        commit="d8e8fe5f92604ef56e11db7f9798973cf94767cb",
+        cache_path="rby1_description",
+    ),
 }
diff --git a/robot_descriptions/rby1_description.py b/robot_descriptions/rby1_description.py
new file mode 100644
index 0000000..e8091de
--- /dev/null
+++ b/robot_descriptions/rby1_description.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2022 Stéphane Caron
+
+"""YAM URDF description."""
+
+from os import getenv as _getenv
+from os import path as _path
+
+from ._cache import clone_to_cache as _clone_to_cache
+
+REPOSITORY_PATH: str = _clone_to_cache(
+    "rby1_description",
+    commit=_getenv("ROBOT_DESCRIPTION_COMMIT", None),
+)
+
+PACKAGE_PATH: str = _path.join(REPOSITORY_PATH, "models/rby1a")
+
+URDF_PATH: str = _path.join(PACKAGE_PATH, "urdf/model.urdf")
diff --git a/robot_descriptions/rby1_mj_description.py b/robot_descriptions/rby1_mj_description.py
new file mode 100644
index 0000000..ee5c0b6
--- /dev/null
+++ b/robot_descriptions/rby1_mj_description.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2022 Stéphane Caron
+
+"""YAM URDF description."""
+
+from os import getenv as _getenv
+from os import path as _path
+
+from ._cache import clone_to_cache as _clone_to_cache
+
+REPOSITORY_PATH: str = _clone_to_cache(
+    "rby1_description",
+    commit=_getenv("ROBOT_DESCRIPTION_COMMIT", None),
+)
+
+PACKAGE_PATH: str = _path.join(REPOSITORY_PATH, "models/rby1a")
+
+MJCF_PATH: str = _path.join(PACKAGE_PATH, "mujoco/model.xml")
diff --git a/robot_descriptions/yam_description.py b/robot_descriptions/yam_description.py
new file mode 100644
index 0000000..2e5bcec
--- /dev/null
+++ b/robot_descriptions/yam_description.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2022 Stéphane Caron
+
+"""YAM URDF description."""
+
+from os import getenv as _getenv
+from os import path as _path
+
+from ._cache import clone_to_cache as _clone_to_cache
+
+REPOSITORY_PATH: str = _clone_to_cache(
+    "i2rt",
+    commit=_getenv("ROBOT_DESCRIPTION_COMMIT", None),
+)
+
+PACKAGE_PATH: str = _path.join(REPOSITORY_PATH, "robot_models/yam/assets")
+
+URDF_PATH: str = _path.join(REPOSITORY_PATH, "robot_models/yam/yam.urdf")