For the BV101-B, powerful is the best word to describe this mini vortexer. With a 4 mm orbit and fixed speed of 2800 rpm, the Vornado instantly vortexes even the largest samples, including nearly full 50 ml tubes. Despite its powerful motor, the Vornado has a footprint of less than 4x4 inches, allowing it to fit on even the most crowded bench. Insta-Touch operation means that the motor is automatically activated with slight pressure on the center cup head. Operation is smooth, quiet and efficient. When pressure is removed, operation immediately ceases. The BV101B Vornado's unique head design prevents liquids from entering the housing, prolonging motor life. This unit comes with a blue colored cup head, and a 115 V US power plug.