New Rival squeegee rubber from Australian company Glidex is compatible with all standard profile squeegee channels, eg Ettore, Unger etc.

High quality slit rubber comes in 36" lengths, perfect for long channels or cut to size as required. That's 2x 18" professional quality rubbers for $7.70 including GST, not bad eh!

Gives great results, and long-lasting too; we use these ourselves. Much cheaper than the others, this just might be your new rubber of choice.
Also available singly.