Inner diameter hole is approximately 14mm which allows a perfect fit for a 14g 5/8" barbell with 5mm balls. If you don't want as snug fit try a 3/4" barbell. Barbell is NOT included.
Outer diameter of the shield is approximately 1-1/4".
Can be worn with 16g, 14g, 12g, or 10g barbells.
These can tarnish over time due to the silver plating. A microfiber cleaning cloth can ensure they stay nicely polished.