This 2GB memory kit from Transcend brand consists of two 1024 MB modules & is ideal for boosting the performance of your old system. The kit runs at 400 MHz & is backward compatible to 333 & 266 MHz. Replace your existing memory or old 256 MB & 512 MB modules completely. The mounting design is very simple because the modules are only clipped on. A software installation is not necessary because the memory is automatically detected by your PC.