It took some time to arrive but at long last, Android 5.1.1 Lollipop has arrived for the older models.

Sony has finally released the Android OS bump which will be available for the following models per GSM Arena: Sony Xperia Z, Xperia ZL, Xperia ZR, Xperia Tablet Z Wi-Fi, as well as Xperia Tablet Z LTE models. The updates should be out by now since the original date of release was pegged for Sept. 9.

But do take note that the update can reportedly be only seeded in certain variants. Here is a list of that which should help guide the ones who are using old Sony Xperia handsets: C6602 and C6603 variants (Xperia Z); C6503 and C6506 variants (Xperia ZL); C5503 only (Xperia ZR); SGP311 and SGP312 (Xperia Tablet Z Wi-Fi); and SGP321 only (Xperia Tablet Z LTE models).

And while the Android bump should be something to cheer about, there is also something that Xperia owners may want to take note of. This has something to do with the Stagefright exploit as singled out on the Xperia blog.

"Looks like the Stagefright exploit has not been fully patched in this update. We will attach some FTF firmware links in this post in due course, but in the meantime, if you have installed the update, let us know your initial impressions below," according to the blog. 

An over-the-air (OTA) update should appear on the device's notification once the Android 5.1.1 is available for application. Simply tap on it and the rest will follow. Do take note that devices equipped with official Android builds are the only ones that may receive these OTA updates.

As far as other Sony Xperia devices not covered in the list above are concerned, it remains to be seen when Android 5.1.1 would become available. Some rumors suggest that there will be devices that could possibly be bumped up directly to the latest Android M (Marshmallow) OS.