From the manufacturer:

ASUS B250 MINING EXPERT LGA1151 DDR4 HDMI B250 ATX Motherboard for Cryptocurrency Mining The B250 Mining Expert has been engineered to provide all the power your GPUs demand, cleanly and efficiently. The 19 PCIe slots are grouped into three distinct zones, each powered by its own dedicated 24-pin ATX12V power connector—reducing wiring complexity and ensuring ample power delivery to all PCIe slots.

Stable, low-noise power is a serious benefit for 24/7 cryptocurrency mining. That's why we've engineered B250 Mining Expert with 19 decoupling capacitors. These quality components smooth voltages and reduce high-frequency noise, so your GPUs get the good-quality power delivery needed for reliable operation.

-What's in the box: -B250 MINING EXPERT motherboard -Serial ATA 6.0Gb/s cables(2) -I/O shield -Support DVD -User's manual: missing