For 0.625″ ARTEMIS 2 Arms/Spring Arms For Volt Gimbal with 5/8″ Arm Post Aluminum Alloy Construction Use the wider Arm Post 0.74 & 0.625″ for Volt Gimbal from ARRI with your Steadicam Volt gimbal with a 5/8″ arm post. This post is also compatible with an ARTEMIS stabilizer arm or spring arm that has a 0.625″ (15.9mm) arm post.