Can be dry wiped from whiteboards and surfaces like glass and porcelain without leaving a trace. Fast drying and low odour. Locked tip. Dry safe, can be left uncapped for days without drying up. Aeroplane safe, automatic pressure equalization prevents pen from leaking on board aircraft. Xylene and toluene free ink. Refillable. Chisel tip size is 2mm. Purchasing each unit.