Review on Gikfun AE1207 12V DC Peristaltic Dosing Pump with Connector - Ideal for Arduino Aquarium, Lab Analysis, DIY Projects by Rebecca Jones

I have this motor that pulls liquid hand washing soap as part of a science fair project for my kid. It works great on a 12v battery and the soap that comes out is just perfect for my project. Tip: The pipe used for the aquarium air filter is perfect for this! So visit the pet shop and pick up the phone there! You won't find it in any hardware store. A few things I would ask the seller for would make it a BEST.1. Can you put an arrow symbol to determine which way is in and which way is out? 2. Can you add instructions for tube replacement? I know it's possible to replace the tube, but I couldn't find any instructions on how to do it.