Handier than an extra pair of hands
They're not cheap, but they're superbly well built and will last a lifetime, making them excellent value for money. Unlike reversible spreader clamps these lower themselves gently in increments, which provides reassuring control and stability. They also have the advance/actuation lever on the top, whereas spreader clamps would have it on the bottom during a lift procedure. That means, somewhat counterintuitively, they go up when you push down on them, so they can be foot operated; ideal when hanging doors and lifting other tall items that you need to be standing up for. Needless to say these can actually fit under a door but spreader clamps can't. And these won't tip over either. I've found many instances where these Tradelifts make my life easier, safer and more pleasurable — Good tools are a joy to use, and these are utterly fantastic.