high quality Suitable Tank: Less than 300L New and high quality. Protein Skimmer use protein separation. Dirt and waste substance collected in the top large container. Components: suction cups, wood air stone, and 49cm long tubing included. You need to use this skimmer with your existing air pump (air pump is not included). Wood air stone generates fine bubbles to separate protein and waste substance from your aquarium. Kindly Reminder: Both of 2 models are suitable for less than 300L fish tank. In order to achieve better bubbles generation, less than 5w air pump is recommended. No need of cumbersome assembly, just attach the suckers to inner wall of fish tank and it works. colour:As shown in color Material:plastic -4003 Flow Rate: 600L/H Cup Size:8*23cm Wood Size (L*W*H): 5x2x2cm / 1.97 inch x0.7 inch x0.70 inch(appr.) Tube Length: 49cm/19.29 inch(appr.) Package Contents: 2 * protein skimmer Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.