Prevelle Silk™ is for smoothing crows feet and 'smoker lines' around the mouth. It is a very thin hyaluronic acid filler mixed with lidocaine. This is a good product for filling in very fine, etched lines around the eyes and mouth. It has lidocaine, which is a numbing agent so no other numbing is needed. Thicker hyaluronic acid fillers are a better choice for deeper furrows and grooves and for facial contouring (cheeks, hollow areas, lips...).
It's thinness makes leaving a lump highly unlikely. However, like all of the hyaluronic acid fillers, it can be erased quickly with the injection of Hyaluronidase (the enzyme that dissolves hyaluronic acid). Prevelle Silk last about 3-4 months and is a good product for those that are new to fillers and are hesitant to use a long lasting filler.