1. Pump performance All three models transport the air with at least 100 –140 mbar, which equals as 1.0 – 1.4 m (3.3 - 4.6 ft.) water column. This means that, for instance, a connected airstone still bubbles normally at 1.0 – 1.4 m (3.3 - 4.6 ft.) water depth. The pressure can be increased to as much as 160 – 170 mbar by combining air hoses. The air 275 R plus and air 550 R plus models include a particularly easy electronic adjustment that allows adjusting the air requirement with a rotating knob. Power consumption is very low at 3, 4 and 8 W. 2. Operation noise The sera air pumps are very quiet. Advice: You will receive the best results when hanging up the air pumps – when doing so, no vibration is being transmitted to a cupboard etc. * 110 Plus * ideal for small/medium aquariums. Sera Air 110 Plus Contents...Sera Air 110 Plus Air Pump x 1Non-Return Valve x 1 * 225 R Plus * ideal for small/medium aquariums. Sera Air 275 R Plus Contents...Air 275 R Plus Air Pump x 1Non-Return Valves x 2Airline Y-Connector x 1 Also includes Sera Air Set Medium, Contents...6/4mm Air Hose x 4mAir Stone x 2Flow Adjustment Valve x 1Non-Return Valve x 2 * 550 R Plus * ideal for medium/large aquariums and Sera Air 550 R Plus Contents...Air 550R Plus Air Pump x 1Non-Return Valves x 4Airline Y-Connectors x 3 Also includes Sera Air Set Medium x 2, Contents...6/4mm Air Hose x 8mAir Stone x 4Flow Adjustment Valve x 2Non-Return Valve x 4 Kindly take note this is a Pre-order item. It will take approximately 3-5 working days to arrive after the order has been placed. Pre-order items are subject to supplier availability. If stocks run out, we’ll notify you for a refund or alternative. Thank you for your patience and understanding.
