It turns out the devices have "proven more challenging to manufacture than expected," and therefore they are being delayed for at least half a month.

The device may also prove useful for medical workers who use computers in sterile environments, he added.

The devices have already proved useful for law enforcement.

However in practice, uniformly reliable devices proved difficult to fabricate.

Even more important, would Tom's new radiation-screening devices prove successful?

The device would have proven invaluable to him right about now.

Unfortunately, Savery's device proved much less successful than had been hoped.

A number of special controllers designed for use with specific games were released for the system, though very few such devices proved particularly popular.

The device and the meters both proved to be accurate.

However, these devices have often proved tricky to pinpoint precisely from the ground.