A device for use with apparatus for installing a cable into a tube, the apparatus including means to mechanically drive the cable into the tube, the device being suitable for directing an air flow into the tube and comprising a bore into which the air flow is directed, the bore having a length and a longitudinal axis, shielding means to reduce air flow from the bore along the longitudinal axis of the bore, wherein the shielding means extends the length of the bore, and wherein the bore is formed from the shielding means.