These cables give you a variety of options for connecting and placing your NVMe Base or NVMe Base Duo.
They have a 'one way' design with 16 pads at the Raspberry Pi 5 end and 18 pins at the NVMe Base end to prevent incorrect installation.
They are designed for PCIe Gen 3 speeds and support Gen 2 perfectly fine also.
The 50mm PCIe Pipe adds some length, while remaining in-spec so you can mount your NVMe Base more comfortable around an existing Pibow or other case, or mount on top/alongside you RPi 5 with a wider range of mechnical setups.