Lexar Professional Series 4 GB 133x Class 6 SDHC Flash Memory Card SD4GB-133-381 Lexar Professional 4 GB 133x Class 6 SDHC Memory Card General Features: 4 GB capacity High-speed performance up to 133x (20MB/s) sustained write speed Class 6 speed rating (minimum write speed of at least 6 MB/sec.) Built-in write protection switch Secure Digital High Capacity form factor (not backwards compatible with SD) Capture high-quality images and video with your SDHC-compatible DSLR camera