With the concessional catch up rule being changed in 2017 you have the possibility of contributing up to $75,000 and claiming it as a tax deduction. This number is reduced by any employer contributions, or personal concessional contributions, since 2017.
An example of the tax savings is; if you are earning $60,000 per year and make a concessional contribution of $10,000 your tax payable would drop by $3,600. Your super fund will pay a tax rate of 15%, so over all you would be better off by $2,100.