This is a great, inexpensive, item that will help with those frustrating moments when your cello won't stop slipping. Lightweight, it fits easily into any gig bag. For students, it's easy to share with them, and on especially slippy floors, it's great to have the student's endpin in the center of this whilst you can put your endpin against it. I prefer using this over a T-Square type device because of the ability to share with a student that doesn't have one or has forgotten.
4 stars for handling only because it doesn't stop slipping on absolutely everything like a T-Square would.