Any alternatives to Nauticam’s $84 viewfinder o-rings?

I would like to have a spare set of o-rings for my Nauticam 45-degree viewfinder. Apparently Nauticam would like me to pay $83 for this privilege. 

Have any of you come up with hardware store alternatives? 
 

An O-ring supplier should be able sell replacements.  You need to know inside and outside diameters of the rings.  The sealing o-rings seem to be a soft silicone, the retaining o-ring seems like a  harder butyl rubber.  Unfortunately you have to measure them to get the dimensions.    This webpage goes through various methods to measure the o-rings: 

https://www.globaloring.com/blog/how-to-properly-size-an-o-ring-the-first-time-around/

I suspect Nauticam o-rings will be metric.  If you have a local supplier you could visit then they may be able to measure them for you. 

53 minutes ago, ChrisRoss said:

I suspect Nauticam o-rings will be metric.  If you have a local supplier you could visit then they may be able to measure them for you. 

Yes, the best option is to bring them to a local supplier. Their cost is less than 1 euro. They should be metric.

This should be embarrassing to Nauticam unfortunately. O-rings cost peanuts and bearing supplier and some auto-parts stores stock them if you don't want to buy online. Silicone O-rings are slightly more expensive, but the retaining O-ring is almost certainly 70 hardness butyl rubber. Really, you don't need spares for these; they will last almost forever.

Actually embarrassing for Blue Water Photo, not Nauticam.

1 hour ago, PeteAtkinson said:

This should be embarrassing to Nauticam unfortunately. O-rings cost peanuts and bearing supplier and some auto-parts stores stock them if you don't want to buy online. Silicone O-rings are slightly more expensive, but the retaining O-ring is almost certainly 70 hardness butyl rubber. Really, you don't need spares for these; they will last almost forever.

I would expect being located in the USA, metric o-rings would be harder to find and you'd need to find a specialist supplier.

On 1/26/2022 at 11:35 AM, Kraken de Mabini said:

The O-Ring Store sells these two O rings, for $0.79 and $0.57 each.  You can order them on line, piece of cake, that is what I do for all my O rings.

To measure their cross section and inner diameter accurately, I use a cheap eBay micrometer, buy a few more O rings than I need and store them in a jar.  I keep a list of O rings and their measurements in my Scuba file.
Also, it is essential to always vacuum test the housing after changing O rings or similar. 

Nauticam VF to housing O rings:

Two 1.3 x 25 mm    $0.79 ea 

 

One 2.4 x 24.6 mm  $0.57 ea

 

https://www.theoringstore.com/store/index.php?main_page=index&cPath=368_12_37  

 

 

Just the other day was thinking I should get a set of spares for my 45°... you just saved my like $80