Voyo mini PC specifications:

• SoC – Intel Atom Z3735F “Bay Trail” quad core processor @ 1.33 GHz (Bust freq: 1.83 GHz) with Intel HD graphics
• System Memory – 2 GB DDR3
• Storage – 64 GB eMMC + SD card slot (up to 128 GB)
• Video Output – mini HDMI 1.4 (Does not support 4K video)
• Audio Output – mini HDMI, and 3.5mm audio jack
• Connectivity – 802.11 b/g/n Wi-Fi, and Bluetooth 4.0
• USB – 3x USB 2.0 host, 1x micro USB for power
• Misc – Power Button, power LED
• Battery – 1,000 mAh battery (Tiny UPS)
  
• Power Supply – 5V/2A
• Dimensions – 126 x 126 x 12 mm
• Weight – 140 grams

For those who use this system for GNU/Linux demand money back.
https://wiki.fsfe.org/WindowsTaxRefund

It would be better if the machines where sold without an OS installed.