The KiwiGrip Roller lets you vary the texture of the KiwiGrip non-skid coating from fine to aggressive depending on the amount of surface traction desired. Use the roller to achieve the texture you desire. For aggressive non-skid allow coating to dry slightly then lightly roll again. The 9" Roller Brush works well on larger boats. For aggressive non-skid coating allow to dry slightly then lightly roll again 9" brush works well on larger boats