and long-lasting: the catalytic core is made of mixing materials of clay and fabric thread, manufactured by a good process to become a porous core, and safe to apply, can service you for a long time What can you receive: the package that you receive includes 2 pieces of oil lamp wick replacements, that the sufficient provides you a wide choice to meet your wick replacement needs in Air control catalytic: the oil lamp wick can be lit with fire, or you can just put in oil bottles, and it has a good absorption effect, that can be applied with aromatherapy bottles and essential oils, bring to your room Proper length: each oil lamp wick replacement measures . 14 cm, and the diameter is about 13 mm/ 0.5 inches, which is the regular size suitable for most catalytic aromatherapy , and please check the size purchase Wide range of applications: these air control catalytic lamp wick replacements can be combined with any catalytic , and you can put on the table, desk, living room, bedroom, kitchen, bathroom, , or other , to purify air and give you a good mood