Package contents: 2 kinds of slide rings with different functions, good for satisfying your different needs and making more fun when playing guitar | Size: both of the slides measure 6 x 2.5 x 2.5 cm/ 2.36 x 0.98 x 0.98 inch in size, please make sure this point before buying the items; Color: clear glass slide and silver metal slide | Glass slide: made of seamless Pyrex glass, and processed from good quality boron silicate which is heat-treated and annealed | Metal slide: made of durable 304 stainless steel with good quality; It can offer superior sustain, excellent intonation, and a clear bright sound | Useful guitar slides: the glass slide can accentuate the middle harmonics of your sound, and provide silky bluesy slide sounds, suitable for pros and beginners application