We summarize the characteristics of flapping current sheet, which have been deduced from CLUSTER magnetic and electric fields and particle measurements. The following issues will be considered: 1. General characteristics (occurrence, dependence on activity level) 2. Polarization and propagation direction of flapping disturbance. 3. The role of a guide magnetic field component in dynamics of flapping current sheet. 4. Ions vs electrons. What are the dominant current carriers?