●attwood PN 5640-4, Model: T500, Inlet Style: Straight, Inlet Length & Diameter: 3-1/2" L x 3/4", Application: Thru-Hull ●Keep your bait and fish alive with the new Tsunami Aerator Mk2 ●FLEXIBLE INSTALLATION: Both 90 and straight inlets and outlets ●FULL BACKWARDS COMPATIBILITY: With previous Tsunami models ●FASTER, SMARTER INSTALLATION: With no sealant or tools required