Sustainable dry-erase markers in medium chisel point offer vivid colors and are long-lasting and precise. The Pilot Begreen dry-erase ink is alcohol based with minimal residual odor. The dry erase markers are vibrant and hold their true colors and chisel shape. Each dry-erase marker can be refilled up to four times, thus making this a reliable and lasting option. Each marker barrel indicates easy-to-follow instructions to swap the refillable ink cartridge. Also, on the back of the package, there is a QR code that directs you to a 1:30-minute video on how to replace ink cartridges. Overall, I am happy with the vivid colors, chisel shape, and lasting performance of the sustainable dry erase markers. One last note, the Pilot Begreen dry erase markers perform exceptional on dry erase boards and glass.