While both devices are budget-friendly, they show off massive batteries, with the M21s and M51 packing a 6,000mAh and 7,000mAh unit, respectively. The M21s' battery also supports 15W fast charging while that of the M51 includes support for 25W fast charging.
The M21s sports a 6.4-inch Super AMOLED FullHD+ display with a water drop notch that houses a 32MP camera. On its back, the phone has a triple camera setup comprising a 64MP main sensor, 8MP ultra-wide camera, and a 5MP depth sensor. The phone is powered by an octa-core Exynos 9611 SoC with a clock speed of 2.3 GHz, paired with 4GB of RAM and 64GB of internal storage. Its storage space can also be expanded up to 1TB via a microSD card slot.
Meanwhile, the M51 features the same set of specs as the Indian model, including a 6.7-inch FullHD+ display, 64MP triple camera on the back, and a Snapdragon 730G chipset. It comes only in a single memory configuration, though: 6GB of RAM and 128GB of storage that's expandable up to 1TB with a microSD card.
The M21s is available in blue and black color options and the bigger model in white and black variants. Both phones can only be purchased online, including via Samsung Brazil's website, with the M21s priced at 1,699 Brazilian Real (~$305) and the M51 at 2,899 Brazilian Real (~$520).