Bravo I XS is designed for Mercury V-6 OptiMax (high-performance and high gearcase height), OptiMax XS, and OptiMax Pro XS outboards.
(pre 2013 Torque Master II gearcase, consider Bravo I FS with PVS)
The dual holes enable the user to fine-tune the amount of venting needed for quick planing.
The shortened exhaust tube provides greater top-end speed while minimizing stern lift for improved boat handling and performance.
Half-inch models enable owners to precision tune performance-oriented bass boats and center consoles for maximum power and efficiency.
And, for some applications, the half-inch pitch will offer additional bow lift for enhanced top speed as well.
Half-inch pitch can benefit on-plane performance, mid-range fuel economy, and top speeds for single engine four stroke applications.