Overview: Designed for testing & using those cell phones that will only boot with a SIM card inserted Perfect for using on a secondary cell phone GSM SIM cards (works on 2G/3G GSM phones) Read-only, non-writable (at least not via typical means) Does not actually work with any cellular operators Specification: Weight Approx: 10g Size Approx: 5.5 x 0.2 x 8.5