Hi AGB - the max that you personally can put in (as a 48 year old) is 25% of salary (as with PRSA, Personal Pension, Occupational Pension).
BUT (and it is a big but) - the company that you work for can also contribute to the SSAS for you - the % that company can contribute is only limited by revenue maximum pension rules, and the most you could contribute would be if you went for a retirement age of 60 (the youngest allowable retirement age in most normal circumstances) - this would mean you could fund for a pension of 2/3rds of your salary at age 60.
I would need personal details to calculate exactly for you how much can go in from company for you, but it could certainly be in excess of 100% of salary.