*Small holes, not for cord
Czech glass is superior because of the clarity of the glass, without haze (like India made glass) or bubbles (like Chinese made glass). What's more, Czech glass is solid color glass which requires skill, quality materials and centuries of work to perfect the recipes for each color variation, unlike Chinese glass beads which are simply cheap transparent clear glass which has been painted with various varnishes. Czech glass retains it's color for centuries, making heirloom quality rosaries long after other finishes have faded or peeled.
Any bead with a measurement like 6/8 or 4/7 the 1st number is the bead width and the second number is the bead length, so a 6/8mm bead is 6mm wide by 8mm long.