The RAM-240U-RM1 consists of a 1.5″ ball connected to a 3.68″ diameter round base that contains pre-drilled holes that connect to Raymarine devices listed below.

This base is designed to hold the following devices:
Raymarine A50
Raymarine A50D
Raymarine A57D
Raymarine A70

Material:
Powder Coated Marine Grade Aluminum

Ball Size:
1.5″ Rubber Ball Size