I bought this one: "2842 globalfix pro cat1 class 2 automatic deploy" Don't know it's worth it to buy a manual one, after watching that video of the boat sinking while picking up traps it reinforces the fact that if bad things happen they can happen so fast that you won't have time to manually activate an epirb. Spend the extra couple hundred bucks on an auto model. I ended up mounting mine so the hydrostatic release mechanism is 18" off the deck, as close to the centre of the bulkhead as I could (ended up between my door and rear steering station), I figured if I have 18" of water at my bulkhead I'm happy with the EPIRB activating. Was easy to install and is easy to test. Don't forget to complete the beacon registry, it was simple to do online.