Indium wire is traditionally used for demountable cryogenic seals - its ductility allows it to deform plastically to make a seal between the flanges and it does not embrittle on cooling.

For new students to the cryogenic laboratory there is our step-by-step video that explains how to make Indium Seals.
0.7mm diameter Indium (99.99%) wire - 10m length
203.58 203.58 USD
1.6mm diameter indium (99.99%) wire - 5m length
299.70 299.7 USD
1mm diameter Indium (99.99%) wire - 10m length
339.12 339.12 USD
2mm diameter Indium (99.99%) wire - 5m length
561.87 561.87 USD