The RHT mags are pre-slotted for S_I/SPS frames and unslotted for Para and other if I understand them correctly. They do export a lot to Auz, but I have heard nothing about quality from their mags. There is another company, HK Precision, in RSA that make S_I mags, very good quality and very cheap, but not on the net. Can get e-mail/tel/fax if required.