A self leveling thin viscosity gel UV/LED Formula. HEMA Free! Designed as a less flexible alternative to "Five" and "SL Clear" When using 2.5 it is not recommended to layer with other building gels ("Five", "SL Clear") as the difference in flexibility may cause pocketing or breakage. Can be used as a one step with Cohezion. When and why would I use 2.5? Repeatedly breaks nails due to extreme length or use of hands. Most will respond best with a flexible resin that moved with them, however we have found that this can also be too much movement for others. This is why we have gels like 2.5. Those transitioning from acrylics will often have better success and less pocketing with a less flexible gel like 2.5 or Pink Sculptor.