Mellanox is the primary source of switches that use its ASICs. Either that, or its list of ASIC customers is very tightly held. HPE (Hewlett Packard) does resell these as m-series switches. The switches were announced in a press release that hearlded the SN3000 family without listing its members. A follow-on document in September 2019 is a lot closer to a real data sheet.

The Spectrum-2 ASIC is capable of PAM4 encoding on each lane, so QSFP56 and 400 Gb/s in a QSFP-DD 8-lane receptacle.

The ASIC claims fine grained buffer statistics with 64 nS interval resolution. The linked white paper was written along with the ASIC introduction in 2017 and a careful reading suggests it may not be entirely accurate. But it's the intent that counts??