Abstract Density-wave fronts in a vibrofluidized wet granular layer undergoing a gas-liquid-like transition are investigated experimentally. The threshold of the instability is governed by the amplitude of the vertical vibrations. Fronts. which are curved into a spiral shape. https://www.spidertattooz.com/G-G-SSG-1-USR-Airsoft-AEG-Rifle-w-Variable-Angle-Stock-ETU-MOSFET-Red/