The Jupiter magnetic compass by C Plath features a flat glass design, Making it ideal for both large and small boats The Jupiter is a sleek, Flat glass ideal for, Magnetic compass both large and small boats. As a Class it serves, A device multiple purposes as a steering compass, Bearing compass, Reflector, And featuring a, Overhead compass card diameter of 180mm, It fulfills Complies with ISO 449 standards and has received type approval dhi/040/01 ma/79 from the German Federal Maritime and Hydrographic Agency (BSH). Additionally certified by the EC Council to meet industry standards directive 96/98/ec. .1000308 Jupiter model 73017 magnetic compass n/shide dimensions mm 261x110x355card Diameter: 180 mm with degree accuracy 0. 5 1000312magnetic Jupiter-style compass 73434, 2060hide dimensions mm 261x110x355card dia. Mm 180 accuracy deg 0. 5