Smartphones, tablet PCs, ebook readers, hand-held game consoles and other devices usually have a limited amount of built-in storage. Transcend's Class 4 microSDHC cards are a cost-effective way to expand device memory capacity and store many times more movies, music, ebooks and app data. Featuring a minimum write speed of 4 MB/s. Transcend's Class 4 microSDHC cards are a smart and cost-effective choice for you to capture and store more of your everyday life with your mobile gadgets. All microSDHC cards are comprehensively tested for compatibility and reliability, and carry Transcend's Limited Lifetime Warranty. Each card contains built-in ECC (Error Correction Code) that automatically detects and corrects errors during data transfer, and also utilizes a sophisticated wear-leveling algorithm for consistent long-life operation.