Wilkins Midsole Marker, a sneakers pen is formulated specially to treat and restore yellowing BOOST midsoles, bring back to life using specialised paint. It is also perfect for tidying up marks and blemishes on your midsoles to get your shoes looking like new again. Just one layer and you can see the difference. With Acrylic-based permanent paint, commonly used by professionals for sneakers customisation. Tips: 1.When using for the first time, shake the marker several times with closed cap. Then open the cap and pump the marker tip on hard surface 15-20 times until paint comes out. 2.Midsole marker head tip can be taken off for a replacement. If the tip falls during usage, can be put back in place.