From Amazon
edding 4095 chalk marker pen set - white - 5 chalk pens - round nib 2-3 mm - medium-nib wet wipe pen for chalkboards, windows, glass, mirrors - liquid chalk marker pens for opaque coverage
Conrad Electronic
Edding 4095 4-4095-5049 Chalk White, White, White, White, White 2 mm, 3 mm
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