Yaen (Japanese fishing method) and horse mackerel cooler protein skimmer, usable with a horse mackerel bucket. The bottom has a hose, so you can adjust the length by cutting the hose and air hose with scissors. The cap (intake) is circular, allowing for 360° adjustment. I think one drain (exhaust) is sufficient if it can handle the exhaust. Comes with a drain cap. The measuring marks are on the left side, 10cm from the cap. All hoses are 6mm outer diameter and 4mm inner diameter. These are air pump hoses. Length: Approximately 23.5cm. Photos 8 and 9 are of my own skimmer in use, not the item for sale. Please refrain from purchasing if you are overly concerned about details. Price reduction is not possible.