apparatus for applying an elastic sleeve to a joint between a pair of electric cables including a tubular cylindrical plastic support with an internal bore larger than the diameters of the cables and on which the elastic sleeve in its stretched state is mounted . a pair of openable mobile elements surround the support , and the element farther from an end of the sleeve is releasably secured to the support , such as by pins extending from the element through openings in the support and engageable with the outer surface of one of the cables . the other element is slidable on the support and can be moved toward the end of the sleeve . a screw mechanism acting between the elements moves them away from each other causing the support to be pulled out of the sleeve . with the apparatus positioned with the support and sleeve around the joint , the removal of the support permits the sleeve to contract around the joint .