Concentrate specific vapes are usually smaller than those for dry herb because they only need to boil off the extract, leaving no residue. In contrast, dry herb vapes have to hold the product at a high enough temperature to vaporize the essential compounds without combusting the herbs, demanding more space to house it and the technology to control the temperature. This is why concentrate specific vaporizers, also known as oil and wax vaporizers, tend to be cheaper and smaller than their dry herb counterparts.