90 duro
https://www.amazon.com/dp/B0052AU2A6/ref=biss_dp_sa1
75 duro
https://www.amazon.com/021-Viton-Ring-Durometer-Round/dp/B003SLE5MC/
Cheapest way to get them. Now there are 10-100 of them per pack, but it's about the same price as getting them in the kits.
O-rings you need
90 duro=high pressure, and should probably be viton
112 -DIN regulator o-rings. If you don't have DIN regulators, don't bother getting them. They don't come out hardly ever unless you have HOG regs, but if you do, you know that and should already have them. $8.30 for 100 of them.
014-Yoke valve O-rings. Need a bunch of these, but at $8.50 for 100 of them, it's worth getting a big ass pack of those
012-HP port plugs and 1st stage hose end. Usually don't need those, just carry some spare port plugs instead. Dive shops will usually sell them to you from the repair bench for a dollar a piece and usually have a bucket of them
003-HP spool o-rings. These are evil and I would just buy some spare spools from Piranha or DGX because they are a right PITA to replace. $8 for 50 of them, but I'd just get 8 spools the same price and never have to worry about it.
If you're comfy DIYing stuff, then 015 is probably a good one to have. $4 for 50 of those. Those are the bonnet o-rings in most tank valves. This one
@victorzamora is well familiar with because it causes the valve to leak when it is opened. Will seal just fine until you try to open it and then it will leak out of the end of the valve knob. Most people aren't comfortable replacing that one, but it's not hard to replace. Up to you on that guy.
75 duro=low pressure and doesn't have to be viton, but a lot of people do just for good measure.
011-LP port plugs and hose ends. Again, I'd just get some spare port plugs from the dive shop. If you have one of these hoses blow you can take them off of your spare port plugs, but they RARELY go as they are a replacement item at service
010-regulator side hose o-ring. You want some of these as they tend to like to go and are often not replaced during service. $6.55 for 100 of them.
so $8.50 for yoke o-rings, $8.30 for DIN o-rings, $7 for LP side o-rings, probably $20 for 5 each spare port plugs, $8 for 5x spare HP spools. Just over $50 and you have a wicked good save a dive kit for O-rings, and it will probably last you the rest of your diving career. It will fit in a real tiny pelican case, or a baby sized tackle box
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