CFexpress 2.0 Type B Memory Cards have two PCIe data transfer lanes and a theoretically maximum speed of 2 GB/s (2000MB/s). The newer CFexpress 4.0 standard doubles this speed to 4 GB/s (4000MB/s). Type B cards measure 38.5mm (width) x 29.6mm (length) x 3.8mm (depth). The Canon R3 & R5 both support Type B cards along with the Nikon Z9, Z8, Z7 II and Z6 II.