Approved lifebuoy

What should be the diameter of an approved lifebuoy by Transport Canada?

When buying a lifebuoy, look for a Transport Canada approval stamp or label. Lifebuoys must be at least 610 mm (24”) in diameter. SOLAS lifebuoys are 762 mm (30”) in diameter. Smaller lifebuoys and horseshoe-type devices are not approved. The lifebuoy must be attached to a buoyant line of not less than 15 m in length which must be securely fixed, and in good condition. Make sure that the grab lines on the lifebuoy are also secure and in good condition. Also, it must not show any tearing, perforation, or mold. It must be quickly accessible in an emergency and is required only on vessels over 9m.