The Nest Protect smoke and carbon monoxide detector is once again available after being recalled on April 3. The recall was prompted by the discovery that the Nest Wave feature did not work properly.

Nest Wave was created as an easy way for owners to turn off the alarm in case in goes off due to a minor accident, like burning toast. By waving a hand in front of the Nest Protect, the alarm would be deactivated temporarily. Testing conducted by Nest later showed that it may be possible for the feature to be triggered unintentionally. Nest immediately issued an update over Wi-Fi that disabled the feature and stopped all Nest Protect sales. The recall affected approximately 440,000 devices, according to the Consumer Product Safety Commission.

"We identified this problem ourselves and are not aware of any customers who have experienced this, but the fact that it could even potentially happen is extremely important to me and I want to address it immediately," CEO Tony Fadell said in a statement.

As of Tuesday, the Nest Protect is once again being sold. The Nest Wave feature is now disabled by default, and the cost has been reduced to $99 from its $129 launch price. Nest is still looking for a solution to the problem with Nest Wave, and hopes to re-enable the feature once it is fixed.

Despite the lack of Nest Wave, the Nest Protect still has a surprising number of useful features. When smoke or carbon monoxide levels begin to rise, the detector issues a vocal warning, informing residents that there may be a problem before sounding the alarm. In addition to a regular alarm sound, the Nest Protect also uses voice alerts when an emergency takes place, telling residents what the problem is and where. The vocal warning may also help wake children, who are more likely to sleep through a normal alarm.

Nest Protect also issues a notification to the owner's phone if smoke or carbon monoxide is detected. It can't notify the fire department like smart alarm systems monitored by a third party, but it does help prevent a fire from going unnoticed when the homeowner is away. The detector also has a light that displays briefly when the lights are turned off to indicate battery level.

Users can still press the button on the front of the Nest Protect to turn off the alarm just as with a regular smoke detector. The Nest Protect is currently available on the Google Play store and Amazon, and will soon be back in stock at retailers such as Best Buy and Home Depot.