See below attachments for P5531 and P5532 Instruction Sheets, along with spare part numbers.
Test Port o-ring (same for both models)
Part Number: 3865195
Description: 54-703-10,O-RING VITON 1/4 X 1/16 X SEC
Part Number: 1785497
Description: 759270-502,O RING -010 70 DUROM 0.239 ID .070W BUNA
P5531 (500 psi or 35 bar)
Chamber o-ring
Part Number: 3905629 (2 required)
Description: 54-700-017,O-RING BUNA-N 11/16 ID X 1/16 XSEC 70 DURO #2-017
---------------------------------------------------------------------------------
P5532 (3000 psi or 210 bar)
Chamber o-ring
Part Number: 3864730 (2 required)
Description: 54-700-023,O-RING BUNA-N 1.051ID X .070 SEC 70 DURO
Parts can be quoted or ordered by/from our Orders Team at orders@flukecal.com or by calling 877-355-3225
Pressure Technical Support can be contact at the below link or the above phone number.