Dorman 02254 Vacuum Bypass Caps - 3/4 In. I.D., 2 Pack Universal Fit

Works fine

It was a good price and they shipped it out in a good time , it was sealed and brand new

If you're here for the same reason I am, you're getting these for your Miata. It works perfectly for making the top spring up, it's a great little mod. Also yes, this does come as a pack of 2.If you'd rather save ~$2 and don't mind getting some extra bits, the same caps are also available in Dorman P/N 02253 which is cheaper as a set for some reason. Available here on Amazon:  Dorman 02253 Bypass Cap Assortment - Pack of 8

Fits perfectly over a soft-top Mazda MX-5 Miata's rubber bumpers causing the top to spring up again.

I used one of these to plug the sound pipe into my cabin where I removed the stupid symposer (artificial engine sound simulating device) on my Jaguar XFR. It fit perfectly and it's doubtful that it needed any type of mechanical faster, but I used a cable tie around it as an extra precaution.FYI, these are the same plugs sold as NAPA 660-1695 for $3.99 for a pack of two at the stores, which isn't a bad thing at all. NAPA says as much on their own website, "That’s where NAPA Solutions steps in with Dorman aftermarket parts."I just posted a question on Amazon regarding the temperature range, as all the Amazon description says is, "heat-resistant vinyl," but I'm not able to see my question on Amazon yet and answer it myself. So, I called the Dorman tech support line and was provided with some great information:These are not actually made from "heat-resistant vinyl," as advertised on Amazon and everywhere else, including Dorman's own website. They're made from NBR (Nitrile Butyl Rubber), and the tech rep informed me that they have a temperature range from -30° Fahrenheit to 250° Fahrenheit, which is pretty standard for NBR. Additionally, I'm aware that NBR typically has great resistance to ageing, fatigue, and abrasion, as well as oil, fuel, and other chemicals (dilute acids, dilute alkalis, hydraulic fluids, and transmission fluids), which makes it a frequent choice in Aircraft, Automotive, Marine, and Off-Road Equipment fuel systems.Anyway, long story short, these seem to be a great and an extremely cost-effective choice for automotive applications like mine, and I expect the longevity to exceed a lot of the other available options, other than potentially the reinforced silicone coolant caps I've previously used on projects, which have a max temp of 350° Fahrenheit. But those silicone caps cost about 1,500%+ more than these, and for my application, where I'm just plugging a vacated, non-contact sound tube, I'm not concerned enough to spend the extra money on silicone.