20 BAF, Clear, English JIM-GEM Square Shape Prism

Square shape offers a larger viewing area. Accurate to ±1% of rated BAF. For general cruising in areas having less than 15% slope. Clear glass prisms perform satisfactorily in most cruising conditions. Amber glass prisms prove superior when cruising is done in low light, hazy or misty conditions. 40 mm x 40 mm. Leather case.