Abstract: A feedthrough device is provided for sealing a supply line as it passes through an aperture in a wall member such, for example, as the housing of electrical apparatus. The device, which is generally tubular, comprises a first member which is radially inwardly deformable and can be pushed through the aperture and a second member which can telescopically engage the first member so as to co-operate with it to clamp against the wall member and provide a seal whilst at the same time preventing radial inward deformation of the first member. A recoverable sleeve member, which may be provided on, or be integral with, either of the first or second members engages the supply line to effect a seal therewith.