Cat 40 Hydraulic  Chuck, 3/4 ID,

RC4HC0750

CAT40 .7500 Bore Dia, Hydraulic Chuck, 2.5197 Gage Length
RedLine Tools
Cat 50 Hydraulic Chuck, 1-1/4 ID,

RC5HC1250

CAT50 1.2500 Bore Dia, Hydraulic Chuck, 3.1890 Gage Length