This is a simple plug valve for watering raised bed system. I use 1poly pipe to run rain barrel water to garden. So that's why 1 inserts were created. You can design different size inserts for your needs. Inserts are glued. All body items 100% ABS, plug 100% PLA (better friction). O-ring on plug form 17 to 22 mm. Silicone lubricant applied inside valve. If you have any question, do not hesitate.