Static grip door and board carriers come in two slightly different designs, but they both work in the same way.
The handle of the carrier with two static grips can move on a pivoting joint. This allows it to be used in either hand and on either side of a sheet of material. When the handle is lifted the sheet is held between the static arms.
The arms of static grip door or board carriers are used to grip a sheet material. The action of lifting the handle angles the arms so they hold a sheet in position between them until that angle is changed. Carriers with three arms are shaped in such a way that whichever of the two outside arms is free can be used as a handle.