The Bel-Art™ SP Scienceware™ Battery Powered Portable Magnetic Stirrer is ideal for field use, great for use in incubators or wherever there are no electrical outlets available. A portable magnetic stirrer in a plastic case 9.25 x 5 x 3.5 in.H (23.4 x 12.7 x 8.89cm). The case has 4 rubber feet, an on/off switch and a speed control knob. The top, attached with 4 screws, is removable for battery change. The stirrer operates on 1 or 2 "D" sized batteries (not included). Carbon/Zinc, Alkaline or rechargeable type batteries are acceptable.