Jet Black Opaque Czech Glass Rondelle Wafer Disc Beads 4mm Czech glass rondelle disc beads available in opaque, translucent, opal, swirl and metallic finishes. 4mm Czech glass discs are small enough for the most delicate of jewelry pieces. Ideal spacer beads on necklaces and bracelets and as accents on seed beadwork/sculptural jewelry. Beads are packed loose, ready to use. Size and pack specifications: Beads are 4mm in diameter. Approximately 100 beads per pack.