While this should be a review for their Boom 3 mount (accidentally ordered a Megaboom3 mount, emailed them immediately and they made the swap ON A WEEKEND! On top of things there at Spartan Mounts!) The mount fits my speaker nicely, not too hard to get in but it's definitely not going to pop itself out. Slides a little left to right if mounted horizontally so we'll see how it does once I mount it in my boat but I can say I'm impressed with initial fit and finish.