O=rings for sea and sea

Help Help I need to replace the o-rings in three sea and sea dx d200 housings (grandson , sons , and wife's housings ) . It has been four years ago .since the last overhaul and I don't have the money to do 4 housings . I am hoping to find o-rings on the net, so I can buy in bulk . thanks for any help you can give .       Lee. 

To take the buttons and knobs apart you will need several small tools including flat bladed screwdrivers, needle nose pliers and similar. It is good to know how to remove and install C clips and similar small retainers. The work area must be well lit and clear, and one should be prepared to hunt for very small items that fall on the floor or otherwise try to hide and escape; a very bright flashlight can be of great help to find dropped small parts.  

I buy the O rings for my strobes and housings from The O Ring Store, and save a fair amount of money compared to buying from a dealer.  To measure an O ring I use a compass to draw circles on blank paper, a mm ruler and a metric digital caliper from eBay, Amazon or similar.
You might also try to obtain an O ring kit from the manufacturer or dealer. (As O rings are tough and long lived, I reuse all the O rings I can as long as they are intact with no signs of damage or softening, but I realize this practice many not meet with wide approval.)
An O ring is described by its thickness and by its inner diameter.  I use the digital caliper to measure the thickness.  The i.d. I measure with the caliper or ruler, and for large O rings a ruler, and I draw a circle of the same measurement on paper to overlay the O ring on it to check the i.d. measurement.

When taking a housing apart, it is important to keep notes, take photos, and organize all the removed parts in groups, in several small jars with labels.  Start with the simplest housing, do one  button or a small group of buttons first. After finishing each batch, test the housing to confirm it is water proof. 

https://www.amazon.com/Digital-Caliper-Adoric-Calipers-Measuring/dp/B07DFFYCXS/ref=sr_1_4?c=ts&keywords=Digital+Calipers&qid=1649288074&s=industrial&sr=1-4&ts_id=2476630011

Thanks Mr Kraken de Mabini that is good stuff . I was looking for info on what type of material  sea and sea uses for the O-ring and what measuring system ( asa or Japan ) sizing chart to use . I find the diffance between ASA and Japans o=rings are a lot a like .I find that a set of hemostats dose a good job of removing and installing e-clips . 

                                                 Thanks for the info

Material is Fluorosilicone O-Rings (FVMQ) but nitril 70shore is cheaper, more available and ok.

Size is metric (Not Japan metric !) 

For the size, i have bought a lot and send back the bad ones.

Happy to exchange if you need more help

Thanks this is what I needed to finish the rebuild. Thanks for the info