Mercury - Bravo I LT Pro - 4-Blade - 150 to 400 HP Outboard - 450R HD Gear Case Only - Up to 600 HP Sterndrive - 15.25 Dia. - 24 Pitch - 48-8M0121597. The Pro Finished Bravo I LT is offered in one-half pitch increments for extreme precision when dialing in engine rpm for maximized performance.. Equipped with (4) adjustable PVS exhaust vent holes offering improved time-to-plane. The 4 blades and full-length barrel support staying on plane during slow tuns, great rough water handling, and excellent mid-range acceleration.. 150 to 400 HP outboard and 450R HD gear case only, up to 600 HP stemdrive.