I have no idea. Try this though: https://www.amazon.com/gp/product/B07X614J38/
I swear by it.
My recommended spout isn't self-sealing, but in all of my research, self-sealing spouts can become unreliable with time. So it seems it's best to avoid them, and when I came to that conclusion, I kept my search for others and I found this: https://www.amazon.com/Olive-Oil-Dispenser-Measurement-Oxidisation/dp/B07X614J38
I haven't bought one yet, but so far it seems to be one of the best spouts, if not the best one.
The only reason I haven't purchased it is, so far I haven't needed to get an aftermarket spout, but one day a while back I thought I was going to need one and so I spent nearly an entire day doing research and this is the only one I found that I felt would be worth purchasing. So, it's the one I recommend to you.
Now, someone might say to me "Go ahead and get one yourself. It's only $17." To most people, yeah $17 is nothing, but not to me. I have to be careful with my money, and so I won't spend $17 on something unless I have to.
Welp, I got my 16oz bottle of Olea True yesterday and I'm giving it 1 star out of 5 because it doesn't have a pour spout (I confirmed it's not supposed to come with one by asking them about it today). Yep! I'm dead-serious: 1 star out of 5 because of this. I don't have a pour spout I can use and I don't have one of those $10+ bottles that come with a pour spout and a funnel because I've never needed these things before. So now this ~$60 bottle of EVOO might end up costing me about $70 at minimum all because they don't include a pour spout in the bottle. At this high price, I expected it to have one.
The EVOO itself is excellent. It has the most well-balanced high-phenolic profile I have ever seen (which is why I decided to buy it), and I can definitely feel it. However, it's a pain in the ass to pour it onto a spoon. It creates an extremely high risk of expensive spillage because there's no control. It also pours "backwards" while pouring carefully which means it runs down the side of the bottle every single time.
I'm trying to make lemonade out of these lemons though because I've always wanted to try these: https://www.amazon.com/Olive-Oil-Dispenser-Measurement-Oxidisation/dp/B07X614J38 So now maybe I will finally try them, but at $18.27 after tax, that means my purchase of Olea True would end up costing me a grand total of $76.82 ($54 for their EVOO minus the 10% discount comes to $48.60 plus $9.95 in shipping comes to $58.55, plus the $18.27 for the spouts). So yeah, that would be $76.82 for a half-liter of high-phenolic EVOO that has a phenolic content of only 1000-1500 mg/kg which is probably close to 1,000 mg/kg at this point because it's been in the bottle for an entire year now. Laconiko Olio Nuovo has a high-phenolic content of 1010 mg/kg and they store it at 57 degrees Fahrenheit in total darkness and with absolutely no oxygen which helps preserve the phenolic content. So I bet my Olio Nuovo is still right at around 1000 mg/kg. Even so, I think Olea True's EVOO is giving me a better health benefit. I can already feel it. So it has that going for it at least. heh
Now yes, you could ask me what my problem is since it looks like I can afford to buy this stuff (because after all, I did buy it without hesitation). That's the thing: I really can't, but I do what I can to make my purchases of high-phenolic EVOO work because the benefits I get from it are worth it. The benefits far outweigh the high cost for me. So it pisses me off that I can either spend even more money now just because the company doesn't include a fucking pour spout, or I can deal with the daily irritation of pouring it without one in order to continue having only paid what I EXPECTED to pay.
FFS, this is a premium fucking product, and so it should at least come with a goddamn funnel because then I could use that to transfer this stuff into my old bottle of Olio Nuovo (after cleaning it perfectly, of course)! At least then I'd say "Ok cool, it has a funnel so obviously it doesn't have a pour spout so therefore I won't open this until I finish my Laconiko Olio Nuovo." but nnnnnnooooooooooooo. No, no, no. They must be too cheap or something to be considerate of their customers. Just stick it into a bottle and sell it! Yeah, good idea! Who cares about making it easy to pour onto a spoon?! Let's make the customer figure that shit out when they open it up.
Yes, I should've asked, but I expected it to have a spout at this price and it was late at night and the weekend's coming up and I didn't want to wait any longer because I don't want to run out of my Olio Nuovo without having another high-phenolic EVOO here at home ready to go. I didn't know how long it would take to get an answer from them (I would've waited for their answer before ordering), and I didn't know shipping would be this fast. I just wanted to make sure I won't have to spend even 1 day without a high-phenolic EVOO. So I took the risk and placed my order, and now I regret it even though the EVOO itself is definitely superior.
They could at least say on their damn product page it doesn't have a pour spout. They need to get to know their competition! "Oh, everyone else has a pour spout in their bottles. We'd better tell our customers right on the product page that we're too cheap to have one". But no, they just leave it up to the customer to find out after they buy it. Well guess what: all purchases are FINAL. Yep! I can't return this to get a refund so that I can keep looking. I'd love to do that! I don't want to put up with this shit for the next month. I've already come extremely close to easily overfilling my spoon. So I'm betting that will happen at LEAST once. Just imagine the mess that will make. After all, it's oil! They've got to be fucking KIDDING me with this shit.
Sigh. Sorry. I was calm when I began typing this. Just.... fucking shit, wtf.
Edit: My review is up: https://oleatrue.com/collections/all/products/2019-harvest-organic-strength-1000-1500-16-fl-oz-bottle-limit-4-bottles-per-order
Edit #2: I gave in and ordered the pour spouts I linked above. Now this bottle of EVOO is costing me $76.82 instead of $58.55.