An expander for mounting a resilient outer tubular article over an elongate article including a chassis element having associated therewith at least one outwardly movable element which is selectably engageable with at least a portion of the resilient outer tubular article, a driver which is movable with respect to the chassis element and is operative to selectably engage the at least one outwardly movable element, when the outwardly movable element is in engagement with the at least a portion of the resilient outer tubular article, for producing corresponding outward motion and outward expansion thereof and an engagement element, associated with the driver, for insertion into the at least a portion of the resilient outer tubular article upon expansion thereof by operation of the driver, the engagement element being configured to accommodate at least a portion of the elongate article.
