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. Drain cap included. 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 22.5cm. Photos 9 and 10 are of my own skimmer in use, not the item for sale. Please refrain from purchasing if you are overly concerned about details. Price reductions are not possible.