As a sufferer from chronic surfers ear, I always use plugs to minimise water penetration behind the ear, to reduce the chance of trapped water exacerbating the condition and then spending the following days hearing through a watery vacuum.  I have used a number of products ranging from soft silicone putty to variable size composite inserts.  Various problems associated with these products.  Putty types prevent water intrusion but totally block out sound, whereas composites leak a little, can pop out and are fiddly to construct, but do have a audible quality.  Hitherto, the latter product was my preference.

I have been using Pro-Aquaz in various development forms over the past 18 months.  The current plugs are more pliable, making them easy to insert, even without using the gel provided.  With the plugs correctly inserted water incursion is zero and the upgraded filter provides at least as good if not better audio as other products (this is an awkward one for me to review as my hearing is impaired in any case).

Probably the best testament is that I dropped one of the plugs on the beach the other day, I was absolutely gutted, but stoked when I returned to the beach to find it sitting on a step; normal service resumed.