The Rock Slide TRS-SB Small Brass Slide

If all you've ever known are cheap, Dunlop slides... You're in for a treat!

The brass is gorgeous to start with, no sad stainless tubes here.

The slide has some comforting weight to it, but not so much that it's burdensome.

The design is very ergonomic. One end of the slide has an open side to let you bend your finger. At the other end the walls gradually become thicker so that your finger fits snugly inside.

Then there's the notched side, which lets you use your ring finger to support your pinky.

You have full control over this slide when using it — it stays on your finger and you can add your ring finger for optimal precision.

The slide is perfect to put on your pinky (frankly it won't fit my other fingers). This gives you 3 other fingers that can still fret chords. However: I have slender fingers, so if you have thick stumps this slide might not fit.

Overall, very happy with this purchase. Yes, it's costs much more than 2 regular slides but it's worth it in playing comfort.

After a few tries and error in searching for the perfect bottleneck I have settled for this one, it fits my pinkie just perfectly and seems to have been designed for my finger. It allows me to learn to slide and for everything riff I start to be comfortable with I always think to try with this.
I know that "my finger" is a very personal criteria, but if you're aware of your finger size and it fits with the width end length description, then go for it, no hesitation.