PRO 2000 

Single-hole non adjustable silent pump
Suitable for fish tanks below 80 L
1 L/min maximum air output
Power consumption: 2.55 W
Number of vent holes: 1
Maximum air output: 1L / min
Product size: 106 × 62.5 × 42 mm

PRO 6000 

Double-hole two-stage adjustable silent pump
Suitable for fish tanks below 200 L
3 L/min maximum air output
Power consumption: 3-5 W
Number of vent holes: 2
Maximum air output: 0.8-1.5 L/min × 2
Product size: 142 × 83 × 56 mm

PRO 9000 

Double-hole multi-stage fine-tuning silent pump
Suitable for fish tanks below 400 L
4 L/min maximum air output
Power Consumption: 3.5W
Number of vent holes: 2
Maximum air output: 1-2 L/min × 2
Product size: 159 × 89 × 57 mm