The adapter is special designed for Mercedes Benz use, it's a perfect match for MP3 player under PCMCIA command system. And support 2GB, 4GB, 8GB, 16GB, 32GB SD cards. Super good quality can compare favourably with the original one. Within the card, the adapter is perfectly fit your car, no extra card expose out. There's a spring inside the adapter, users just gently pushing the card, the card will popup automatically. And users can keep the adapter inside the car if you like and press the button beside to unlock when not need. This adapter also can support address book and other files which under the PCMCIA Command System. Features: Fits PCMCIA Command System Support SD(HC) card. Support SD Card: 2GB, 4GB, 8GB, 16GB, 32GB 64GB Low power consumption. No noise affect. Perfectly match. Strong data security. Best replacement of CD. It is small size and light weight. With longer life and safe to use.casta