The Pentel Chalk Markers come in a pack of 7 vibrant colours which include red blue yellow white orange purple and green.The liquid chalk markers consist of a semi-permanent formula which can be used on all non-porous surfaces such as glass blackboards and whiteboards. The ink can be removed with a damp cloth or non-bleach based cleaner.The Pentel Chalk Markers have a chisel tip of between 4mm and 2mm with a value-activated flow system which prevents blobbing or leaking which ensures you get the most out of the chalk markers.