These Giant Bow Compasses are all made from nickel-plated brass to last for years, as well as coming in a hard plastic case for protection. All of them have micrometric adjustment and also come with a shoulder needle and a container with 2 leads.
Basic model bow compasses.
This model has double knee joints and a removable pencil attachment.
This model also has quick release mechanisms to override the micrometric screw adjustment, plus a lengthening bar and adaptor.