Free Chack Glue is completely free from organic solvents and made from 100% Liquidized natural caoutchouc (natural rubber). After a short drying period, it sticks the sponge and the blade surface together perfectly. It is also very easy to remove the rubber from the blade and to peel off the remaining glue from the sponge. Also available in a 500 ml bottle that includes 50 sponges & a clip and a 37 ml bottle that includes 8 sponges & a clip.