A multi-purpose dosing and fluid delivery system of uncompromising quality combined with the simplicity of Apex Fusion software wizards for operations such as: 2-part dosing (Calcium and Alkalinity) Other additives dosing Automatic water changes micro-quantity dosing delivery of liquid foods and supplements Stepper Motors Make all the Difference Precision With the stepper motor pumps on the D?S, you have precise control each time you dose. And, you are guaranteed it will stay calibrated pretty much forever. On the other hand, with the standard DC motor pump found in most dosing systems, it cannot dose small quantities with ongoing accuracy and consistency. They also require ongoing calibration to account for the wear of the motor and the mechanisms. When pumps fall out of calibration, they dose either too much or too little never a good thing considering an overdose to a tank will often be its demise. Variable Pump Speeds One of the great features of the stepper motors on the D?S pumps is that they can be driven at various speeds depending on the purpose for which they are being used. For instance, dosing of vodka may require the slowest possible rotation while a water change use requires a much higher pump speed. The best part is that Apex Fusion wizards automatically select the proper speed based on the use and because of the stepper motor, accuracy is not compromised even at the higher speeds. Gearing and Drive Mechanism The D?S uses a direct drive mechanism that will not slip, it will not strip, it will not grind to a halt. On the other hand, many other peristaltic dosing pumps used for aquariums have gears that can (and do) strip. Or, worse yet, some pumps work by using the friction of rubber rollers on the smooth metal motor shaft to make the pump spin. Foreign matter like salt creep, additives, etc. often get into the drive mechanisms of these pumps and make them fail or pump unknown amounts. Lifespan The stepper-motor in the D?S has a MTBF (mean time before failure) of 5000 hours. Other systems with brush-driven DC motor pumps have lifespans measured of just a few hundred hours of use. This means the pumps on the D?S may have up to as much as 12x the lifespan of others. Built Secure, large diameter tubing connections Simplified interface Replacement parts Aqua Bus connection to your Apex Accessory port Quiet operation Stylish yet functional design Specifications Size (Approx.): 9.5? x 5? x 5? Weight (Approx.): 4 pounds Lift Height: 24 feet (minimum at MSL) Suction Height: 24 feet Flow Rate: Variable (0.1ml 250ml/min) Power Requirement: 110/120V or 220/24oV Requires: Apex, Apex Lite, or Apex Jr.