I just finished replacing all my shop T8 bulbs with these which are directly replaceable for modern T8 ballasts. However, they also work without a ballast directly from 110V or 220V. I started by simply removing the old T8’s and replacing them with the new. I then got rid of the ballasts altogether which took about 10 minutes per fixture. They have more light and really white light (5000K) which I really like. Amazon has them on sale for $34.99 for four or less than $9.00 per bulb!