VEVOR 75FT x 1/2 Inch Drain Cleaning Machine, 370W Electric Drain Auger, Portable Sewer Snake Auger Cleaner with Cutters & Air-Activated Foot Switch for 1" to 4" Pipes, Black, Red

Do I have to manually keep pulling this snake spring and feed it into the drain or does it automatically come out? The manual part takes a lot of strength to pull this snake.

How do you reverse cable to back out of drain

Is it safe on plastic pipe

Does the cable power feed into the sewer duct or do you have to manually push it in and manually pull it out of the duct ? What is the purpose of reversing the cable after it is insisde the duct? Does that help removal?

I bought the 75 ft auger. Wondering if I can add pieces to it to make it longer than 75 ft?