Optimize filtration and enhance control with the Reef Octopus Stackable Neck Extension. Designed for Reef Octopus skimmers, these extensions increase the neck length for improved contact time with dissolved organics. Compatible with various models, including NK-110, NK-150, NK-160, NK-170, NK-200, NK-250, NK-300, NK-150-TL, NK-200-TL, NK-6000, NK-XP8000, NK-7-8000, and NK-9000ext. Choose between white PVC "Twist & Lock" extensions for Elite and Prime skimmers or black acrylic traditional o-ring extensions. Upgrade your skimmer's performance without purchasing a new one.