The Spenco Women's Lower Back Support insole provides rigid stability that increases foot balance, helping to guide the foot through proper movement. Increased motion control allows the muscles and tendons in the feet and legs to function more efficiently and reduce pain and discomfort in feet, knees and back. The rigid stability cradle was engineered to provide advanced arch support, deep heel cupping and comfort through the stride. Forefoot perforations increase flexibility and air flow for more breathability. This insole is intended to fit women's shoe sizes 5-11 and may be trimmed as needed for a true custom fit. To trim, simply remove the existing insole from your shoe, line it up with your new Spenco Lower Back Support insole as a guide and trace with a ballpoint pen. Carefully cut with a sharp pair of scissors, then insert into your shoe with the top side up.