HAWKING PN580U Data/Fax Modem 56Kbps USB V.90 (down-stream up to 56,000 bps). V.34bis, V.32bis, V.32, V.22bis, V.23, V.22, V.21 Error Correction Protocol V.42 and MNP Class 2 to 4 Data Compression Protocol
SmartLink 56,000 bps Internal Voice Fax Modem By Archtek v.90 PCI BUS | eBay
56K FAX MODEM VD56SMS VOICE DATA FAX 56000 BPS NUOVO lrx
I found my two first modems in the shed. : r/mildlyinteresting