1.5″ Ball Mount w/2.5″ Round Base, Short Arm & 1.5″ x 3″ Plate f/Humminbird Helix 5 OnlyThe RAM-202-153-B-202U consists of a round 2.5″ diameter round base (Universal AMPs Hole Pattern), short double socket arm and 1.5″ x 3″ rectangular base. The rectangular base contains four holes with a center to center pattern of 1″ x 2.5″. For most applications, mount will support up to ten pounds.Features:Compatible Devices: Humminbird Helix 5Center to Center Hole Pattern: 1″ x 2.5″Weight Capacity: 10 lbs.Overall Height: 5.225″Material: Powder Coated Marine Grade AluminumBall Size: 1.5″ Rubber Ball SizeNote: The “U” in the part number reflects product packaged in poly bag. Hardware for mounting to device not included with purchase.Weight: 0.19 lbs.