Moulded Glass Rock Slides are individually hand moulded by master lampworkers. These feature the Knuckle Cutaway, Finger Rest and Tapered Interior. These fit almost exactly like their brass counterpart but are slightly longer. The main difference being that they are much lighter & faster so you can really cook with these on an electric guitar. They ALL feature a 4mm thick wall. Because of their unique tapered interior design they do have enough mass to light up your acoustic.
How Should a Rock Slide Guitar Slide Fit?
Forget everything you’ve read in slide books or heard from your guitar teacher saying you need giant slide with full string coverage. That’s old news. Ideally these should fit snug enough that you can point your finger straight down at the ground without the slide falling off. The proper fit is for the slide to stop at the large knuckle creating a 2/3 finger slide. This allows you for bending of the finger with the slide on which makes, playing, fretting and chording MUCH easier. Full finger slides feel like wearing a cast which is limiting and not recommended unless you already have this habit and know you like it this way.