Made of super soft gum material, safe and it doesn' t hurt human skin. Easy to Use, put the gel on any surface for a while, then remove gently as a whole. (Tips: This cleaner may leave small amounts of residue when used on your keyboard. This will not cause any potential issues. A pipe cleaner or cotton bud can be used to remove the residue.) Reusable, can use it over and over again till compound turns into nontransparent without the need for being cleaned.