While some flash drives focus on being waterproof (Flash Voyager), ultra-durable (Flash Survivor GT), or very flat (Mega-Kart), the A-DATA PD18 is designed to have an extremely small form factor. The A-DATA PD18 is very small and is about the size of the OCZ Ultra-Slim Mini-Kart.
The PD18 casing is made of aluminum with the A-DATA logo on one side and the other is bare. The flash drive itself is just a bit longer than the length of a USB 2.0 connector. The key chain part of the PD18 can be easily attached to the flash drive connector itself and serves as a cap holder when the USB flash drive is in use.