At its Build 2014 conference today, Microsoft made a slew of software and hardware announcements – including the budget Nokia Lumia 630 and 635 smartphones.

Nokia has built a significant part of its business in recent times on lower-end feature- and smartphones, particularly aimed at emerging markets. And taking to the stage in San Francisco, Stephen Elop unveiled the two latest ‘affordable’ Lumia devices, before revealing that these two would in fact be the first devices to get Windows Phone 8.1, the much anticipated update to its mobile OS that was announced shortly before.

lumz Nokia unveils the budget 3G Lumia 630 and 4G Lumia 635 smartphones

The 635 incarnation features 4G LTE, while the 630 will sport a 3G single-SIM version and a 3G dual-SIM variant – both will come with quad-core 1.2GHz Snapdragon 400 processors, 4.5″ ClearBlack screens, and be available in five colors with changeable shells. The 630 (single SIM) will cost $159, 630 (dual-SIM) will set you back $169, while the 635 will weigh in at $189.

The 630 and 635 will be available from May starting in Asia, and will be gradually rolled out to other regions over the next couple of months.

Meanwhile, check out Nokia’s own hands-on video of the new devices below, or have a peruse of our coverage of the higher-end $599 Lumia 930 smartphone, also announced today.