Reef Octopus Protein Skimmer Cup Drain Tubing Part # ROP-TUBE-1532
 
Surgical Grade / Thick Wall Silicone 
Hose length is one foot
Fits all Reef Octopus Skimmer Models
Connects to the collection cup's drain
15/32 ID (when measured on 32nd tape measure) 
9/16 OD  Standard Tape Measure (The most commonly used)
 
*Note - You will need a waste collection container / sold separately