This heavy boom arm comes with counterweight. The arm can be used universally and fits every light stand up to a diameter of 3 cm. The reliable eccentric cam clamps around the tube and provides a multifunctional application: the arm can be moved in any position you want. With a boom arm you can hang your studio lighting above your subject, without it being visible in the picture/video. You also create more freedom because for instance you can walk under the lighting.