Bennett 12x9 BOLT System w/Adjustable Upper Hinge [BOLT129ADJ]12x9 BOLT System with Adjustable Upper Hinge Properly sized trim tabs improve the performance of your boat by adjusting the running angle of your vessel. Bennett Marine trim tabs help you get on plane faster, correct listing (roll), improve visibility, and increase overall efficiency and control. Features: Get on plane quickly to see over the bow Increase vessel performance and efficiency Correct listing (roll) Adjust the boats attitude for changes in