This is a replacement drum designed for Levelor 1" mini blinds. The drum measures 1 ½" in length, and has a 5/32" rectangular hole for the tilt rod. These imperial measurements are what I could find based on parts sellers, the file itself is designed in metric units.

Printing Instructions

• When importing into your slicer, it may warn you that some parts were designed in inches. This is not correct, I did not have the slicer adjust what it thought was in inches.
• I designed the part in the opposite orientation it should be printed in. I flipped the part after importing and enabled supports as shown:

What is a drum?

If, like me, you didn't know the name for this part, the drum is the bit that slides on the tilt rod, which the two strings on the front/back of the blinds attach to to tilt the blinds open and closed. A diagram which explains which parts are which can be found here.