A metal bar underneath the seat is moved up and down with quick release button. (carseat.se)
There are two buttons on the backside of the watch body which serve as quick release buttons for the strap. (pocketnow.com)
To tackle tricky terrain, the Oyster 2 Pushchair in Mirror / Black Tungsten Grey gives you lockable front swivel wheels, that can be easily released thanks to a quick release button, as well as puncture proof tyres to ensure that you're safe and stable at all times. (babyandco.com)