The Manfrotto 131DDB Tripod Accessory Arm for Four Heads mounts onto the center column of tripods with 3/8" threads. The platforms feature 3/8" screws, which allow a standard tripod head to be mounted on either or both sides. In addition, the horizontal bar features 3/8" screws on both ends, allowing mounting of tripod heads from the sides.

Replaces part number 3153B.