These printers use the 39V2971 cartridge:
IBM Infoprint 1870 DNX MFP
IBM Infoprint 1870 DTX MFP
IBM Infoprint 1870 DNX
IBM Infoprint 1870 DTX
IBM Infoprint 1880 BDX MFP
IBM Infoprint 1880 FDX MFP
IBM Infoprint 1880 TBX MFP
IBM Infoprint 1880 TFX MFP
IBM Infoprint 1880 BDX
IBM Infoprint 1880 FDX
IBM Infoprint 1880 TBX
IBM Infoprint 1880 TFX