The Parker Alum Block is made from the highest and purest natural Potash Alum. Many less expensive bars are from chemically derived components.This bar is great for treating minor shaving cuts and nicks as wellas an aftershave treatment with antiseptic properties. To use, simply wet the bar in cold water and rub the bar against your skin. Wait 30 seconds or so, and then rinse. You will feel the antiseptic in action. Also comes in a nice plastic case, great for storage and travel.