Bulldog round jacks are recognized as the industry standard by leading agricultural, commercial, horse, livestock, and other trailer manufacturers. For more than three quarters of a century, Bulldog jacks have been demonstrated to be the most reliable, field-proven jacks on the market. Bulldog A Frame Round Jacks offer easy cranking and smooth, ergonomic design for lighter load requirements. Available with a wide range of features to enable a custom match to your specifications.