Automatic Activation Devices.

Australian Parachute Federation Op Regs May 2012 state:

8.6 AAD and RSL Requirements    
• (a) All freefall descents made by parachutists who hold up to and including a Certificate ‘C’ must be made with equipment fitted with an operational AAD
   
• (b) All freefall descents made by parachutists who hold a Certificate ‘D’ must be made with equipment fitted with either:
•       
  • (i) A functional RSL; or
        
  • (ii) An operational AAD

So you need to get an AAD