Apple’s iOS 12 update is landing today and it’s filled with tweaks that should improve performance — even on older devices. The update is now available for download and has arrived on more devices than ever before. You can check out how to upgrade to the new iOS here.

Apple was keen to point out in its Worldwide Developer Conference keynote that iOS 11 had reached an amazing 81 percent of all active iOS devices, and all of the devices that were qualified to receive the iOS 11 update would also be receiving the iOS 12 update. Which devices does that actually mean? Five years worth of devices are applicable for the update, and even within Apple’s tightly controlled and well-kept garden, that is a lot of devices. We rounded them all up so you can easily check.

There are some devices on this list that won’t surprise anyone. As the latest devices, it was always going to be a certainty that the iPhone X and iPhone 8 range would be getting the update to iOS 12, and given how long Apple tends to support devices for, the iPhone 7 and 6S range also seemed likely.

There are a few surprises though — chief among them is the inclusion of the iPhone 5S. The iPhone 5 and 5C was cut off from iOS updates with iOS 10.3.3, so it was likely that the 5S would be seeing an end to support with iOS 12. The same could have been said for the almost four-year-old iPhone 6 range. We’re happy we’re wrong — these devices received iOS 12, which is a nice surprise.

Not included are any iPhones that didn’t already receive an iOS 11 update, such as the iPhone 5, 5C, as well as the iPhone 4S and earlier. You will need to upgrade your iPhone if you want a chance to play with the newest version of the operating system.

There are a couple of solid rules you can follow when checking up on this list — if you own an iPad Pro, then you have the option to update to iOS 12, and it’s the same story for both models of the iPad Air as well.

It’s a little more complicated when we turn to other models. Every iPad Mini received the iOS 12 update — except for the very first iPad Mini. If you’re in ownership of an iPad simply titled “iPad,” then you best hope it was made either this year or last year, as none of the original run of the iPad — from iPad 1 all the way to the iPad 4 — have iOS 12. If you’re not sure which iPad you own, the best option is to check your current version of iOS under your Settings. If it lists any version numbers other than iOS 11, then you’re not getting iOS 12.

Unfortunately, all consumer technology has a shelf life, and while you’re free to use a device until it drops dead, manufacturers tend to set their own limits. Manufacturers will generally support devices for up to two years, supplying new updates and security patches, though it does tend to vary. Apple is considered better than most other manufacturers in this regard, and will commonly support a device for a longer period of time. The range of devices updating to iOS 12 is particularly notable in this regard since it contains the iPhone 5S — an almost 5-year-old device. For comparison, the iPhone 5S came out the same year as the Samsung Galaxy S4 — which received its last major update in April 2015.

Even with Apple’s longevity, there is a limit. The devices not supported for iOS 12 are 32-bit devices and the ones that are supported are 64-bit devices. Sometimes, the hardware just isn’t capable of handling the demands of the new OS version.