very easy to install. Glad I got this valve instead of purchasing a new snorkel.

I use the Finis Swimmers snorkel for lap swimming anywhere from ½ to 1 mile three times per week.  When I first used the snorkel I would have to blow out water every lap.  Another swimmer showed me how to reposition the one-way valve so half of the valve protrudes from the snorkel.  The water leakage reduced significantly to where I would need to blow out water about every tenth lap.  

Now, about the replacement purge valve.  The original valve fell out in transit and was lost.  After installing the replacement valve, the leakage even decrease further, PLUS breathing improved significantly.  I had not realized how restricted both inhaling and exhaling had been.  I do not understand how the purge valve could affect the back pressure, but it.

The Replacement Purge Valve still fills with water but only after swimming couple of hundred yards which is a slight improvement over the original valve. I have not had this problem with purge valves on regular snorkles.  The manufacturer is the problem. He is  producing an inferior product that he has failed to correct after many similar complaints. This is unfortunate because the overall design of the product is vital to those of us who cannot swim free style anymore because of physical restrictions. Fix the valve part, the rest of the design is great.

So Glad to find this piece to a very expensive snorkel that I now do not have to replace!

I ordered the blue valve. When it came it was a completely new design from the original green that came with the snorkel. It actually worked much better than the original that would tend to leak and needed to be fiddled with constantly.

Originally my snorkel leaked at the collar and I devised a repair with auto parts.  Now, after more than 500km (documented), the valve needs replacement.  I get in the gym for the 17 years and under price...well the senior discount, actually, so I consider this a freebie!