The ASUS PRIME B660M-A D4-CSM is a micro-ATX motherboard with an Intel B660 chipset and LGA1700 socket. It supports 14th, 13th and 12th generation Intel Core processors, plus Pentium Gold and Celeron; compatibility depends on the specific processor.
Four DDR4 DIMM slots support dual-channel memory up to 128 GB. One DisplayPort and two HDMI outputs connect displays, with graphics features depending on the installed processor.
For expansion, there is one PCIe 4.0/3.0 x16 slot and two PCIe 3.0 x16 slots operating in x4 and x1 modes. Storage connections include two M.2 Key M slots for 2242, 2260 and 2280 drives, plus four SATA 6 Gb/s ports. Intel 1 Gb/s Ethernet provides a wired network connection.
The board measures 24.4 × 24.4 cm. Package contents listed by ASUS: two SATA 6 Gb/s cables, an I/O shield and M.2 SSD mounting accessories.