Plate compactors fall into one of three categories: single plate compactors that move in only a forward direction, reversible which move in forward and reverse, and high performance/heavy-duty plate compactors. The handle of a plate compactor plays a key roll. It can be mounted in the center or back of the unit. It can be a swinging handle allowing for easier maneuverability. And it could also be an anti-vibration hadle for increased operator comfort. Equipment is a key element in paving and pavement maintenance.
When hovering, hummingbirds hold their bodies upright and flap their wings horizontally in a shallow figure-8. As the wings swing back they tilt flat for a moment before the wings are drawn. Most hummingbirds flap their wings about 50 or so times a second.
One of the fastest birds is the green violet-ear hummingbird. It can fly up to 93 miles per hour (150 kilometers per hour) for short distances. Hummingbirds are so quick that they can easily escape predators like snakes, falcons, jays, toucans, and cats, unless they are taken by surprise.