What the thread found

• The PRO arm is fully compatible with a Tiffen vest and sled
• The PRO arm has a 0.625 diameter post while the Tiffen Ultra2 gimbal handle socket requires a 0.740 diameter, necessitating an adapter
• An adapter post can be purchased, custom-machined, or improvised using a thin-walled sleeve secured with adhesive or thread-locking compound
• The PRO vest has an undersized socket block that can create compatibility issues with Tiffen and other arms
• Socket blocks can be swapped between PRO and Tiffen vests as they share the same mounting hole pattern and screws

Depends on

• The thin-walled sleeve solution requires adhesive or thread-locking compound to prevent it from slipping off
• Socket block compatibility applies specifically between PRO and Tiffen systems; other arm brands may have different socket specifications

Parts

Arm Post

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