Among the shared hardware specifications between the two would be a 64-bit MediaTek MT6735P chipset with a 1GHz quad-core Cortex-A53 CPU, 1GB RAM, and 8GB of internal memory, accompanied by a 13MP shooter at the back with a LED flash as well as a 5MP front-facing camera. Not only that you get dual SIM support to boot, as well as Bluetooth 4.0 and Wi-Fi connectivity, microUSB 2.0, and GPS with A-GPS.
The Archos 55 Helium Plus will differ by sporting a 5.5” 720p IPS display with 267ppi, running on a 2,400mAh battery, while the Archos 50 Helium Plus will have a sharper 5” 720p IPS display with 293ppi, accompanied by a smaller 2,000mAh battery.