The invention relates to a unit for optionally delivering compressed air or a mixture of compressed air and dry ice for a dry-ice blasting device, comprising a delivery line, to which a feed line for compressed air and dry ice can be connected, and comprising a first and a second switching element which can be connected to the dry-ice blasting device via a control line, wherein the feeding of compressed air can be switched on and off by means of the first switching element and the admixing of dry ice to the compressed air to be fed can be switched on and off by means of the second switching element. In order to develop the unit in such a way that it is simpler to manipulate, it is proposed according to the invention that the second switching element be actuable independently of the first switching element.