Steel external tube diameter: 40 x 1.2 millimeters Aluminium internal tube diameter: 35 x 1.2 millimeters Steel squared base: 35 x 1.2 millimeters Speaker and monitor stand with telescopic tube structure: steel external tube diam. 40 x 1.2 millimeters and aluminium internal tube diameter 35 x 1.2 millimeters. Steel squared base 35 x 1.2 millimeters. Such features make the stand, among its range, the strongest and more stable in the market. Innovative design. Automatic push button mechanism that allows the tube lift but avoids the fall. To unblock the tube just a small pressure on the button is needed. The steel security pin is all in one with the button. The final fixing of the tube is granted through an ergonomic knob covered in rubber that, thanks to its particular shape, allows the maximum pressure with the minimum difficulty or effort.