ASUS Hyper M.2 X16 Gen 4 PCI Express PCIe 4.0 Expansion CardThis isn't just for ASUS but you do want to make sure your mainboard and processor combo have enough lanes so that the slot you put it into isn't bifrucated to the extent that whatever M.2 NVMe drives you install to it, are slowed. Also even the ASUS info below suggest this requires RAID in your motherboard, it does not. It just supports it because the slots will present as "native" NVMe drives to the Mainboard. You can also just let them be single drives.
Example:if you install it into a slot that could be 16 lanes but is only 4 due to some other slot or lane constraint of your system, it will operate one M.2 Gen 4 NVMe drive at 4 x 4. If you have 8 lanes it would do two slots at 4 x 4, so on, so forth. ASUS provides a great slot ocupy/placement guide on their site to maximize throughput in various bifurcation scenarios.From ASUS website:

ASUS Hyper M.2 x16 Gen 4 Card (PCIe 4.0/3.0) supports fourNVMe M.2 (2242/2260/2280/22110) devices up to 256 Gbps for AMD TRX40/X570 PCIe4.0 NVMe RAID and Intel® platform RAID-on-CPU functions

• Two-phase power solution with up to 14-watt output supports the latest NVMe drives
• Large heatsink and active fan reduces M.2 SSD temperatures for unthrottled transfer speeds and enhanced reliability
• Adapted server-grade PCB supports up to four PCIe 4.0/3.0 M.2 drives, with up to 256 Gbps bandwidth for smooth data transfers
• Compatible with AMD TRX40/X570 PCIe 4.0 for NVMe RAID and supports Intel® platform RAID-on-CPU functions
• Also support other vendors’ motherboards via PCIe bifurcation in BIOS setting