The best way is to contact their customer service
Email: info@vacuumciti.com
Phone: 703-635-7521
Measure the length of hose needing replacement.
If it has fittings on either end, allow 4" to 6" more.
measure the hose diameter, both outer and inner.
Choose a color.
When you contact them, tell them you'd like to replace
the hose on a Kenmore canister vac, and that the part
is no longer available from any supplier.
They may want the model# & part# to check their inventory
or the Sears parts catalog for dimensions.
They probably won't have the actual Kenmore part, so ask
if they would sell you a length of matching hose, and give
advice on how you can attach it to your fittings.