m303exceria microsdxc m303 a1 64256gb. hk$ 70.00 – hk$ 228.00. toshibaBÖHLER M303 EXTRA is a corrosion-resistant, martensitic chromium steel with very good toughness, corrosion resistance, good wear resistance and improved machinability and polishability. Compared to 1.2316, BÖHLER M303 EXTRA