https://www.zatkoff.com/parts/o-ring-cord-spliced-rings/spliced-vulcanized-o-ring-15-000-id-x-0-375-w-fkm75-si0375-15000-v-fkm75
O-Ring Cord & Spliced Rings | SPLICED VULCANIZED O-RING 15.000 ID X 0.375 W FKM75...
o ring cord
https://store.easternseals.co.uk/size/bs230v575-fkm75-63-09-x-3-53mm-black/
BS230V575 FKM75 63.09 x 3.53mm BLACK Archives - Eastern Seals Store