I think this is a great subject and am in awe of Eric's goggle design - as it seems like the best system available to ensure hands free equalisation. It should add about 10% onto your maximum frenzel/valsalva equalising depth.
However, you can get half the benefits for a fraction of the cost. We have seen several pipe-masks on this forum - I was even tempted into making my own - the lowest volume of all pipe-masks I have seen so far! But I think that is what Paul's Part II article might be about - so I won't go into it.
I thought I would add another option to list for people (of which many may already be aware - but it is always good to spread the knowledge) - as Paul says this can make a great addition to your diving. I happen to have 'good' ears and don't need to squeeze my nose normally, but sometimes I do - when I have a cold or when the water is really cold or whatever. So I use this system:
I wear a synchronised swimmers nose clip inside my mask and it provides enough back pressure so that almost anyone can equalise with this method. With a really strong puff - you can clear the mask too. Just be sure to get as much grease off your nose before you put on the noseclip and it will sit tight for an entire dive. Hand's free equalisation for a pound!

However, you can get half the benefits for a fraction of the cost. We have seen several pipe-masks on this forum - I was even tempted into making my own - the lowest volume of all pipe-masks I have seen so far! But I think that is what Paul's Part II article might be about - so I won't go into it.
I thought I would add another option to list for people (of which many may already be aware - but it is always good to spread the knowledge) - as Paul says this can make a great addition to your diving. I happen to have 'good' ears and don't need to squeeze my nose normally, but sometimes I do - when I have a cold or when the water is really cold or whatever. So I use this system:
I wear a synchronised swimmers nose clip inside my mask and it provides enough back pressure so that almost anyone can equalise with this method. With a really strong puff - you can clear the mask too. Just be sure to get as much grease off your nose before you put on the noseclip and it will sit tight for an entire dive. Hand's free equalisation for a pound!