Not as slick as Pyrex, brass pr chrome, this slide still has a nice, resonant tone.  It seems to me to being closer to glass than other ceramic slides I've used, but is, again, not quite as slick.  It also has a substantial feel, and is a bit thicker than Dunlop heavy Pyrex slides, and a lot thicker than heavy brass slides.  I don't have particularly large hands (what Dunlop calls a medium usually fits my pinky about right), and this slide fits perfectly on my pinky.  I've had good results on both resophonic and electric guitars.