Random-orbit sanders have three main types of handle. Some models combine all three handles in one device, while others may only have one or two.
Palm grip
The palm grip is a common feature of many random-orbit sanders.
The palm grip allows you to have full control over the sander while its ergonomic grip promotes comfortability and reduces hand fatigue.
D-handle
The D-handle, or “jug handle” as it is sometimes called, is a secondary handle for extra control and support.
Many users find using both the palm grip and the D-handle advantageous because it provides you with the control to apply just the right amount of pressure while maintaining full control over the direction of movement.
Barrel grip
The barrel grip provides the user with another way of holding and controlling the sander.
The barrel grip allows the user to hold the sander by the body. This promotes greater manoeuvrability, though you may get less control over downwards pressure.