The present invention relates to a gel sealing device for sealing a passage of elongate parts through an opening. Such gel sealing device is preferably arranged in a housing used in telecommunication technology. The inventive gel sealing device comprises a gel sealing block (5) which provides a sealing section (22) through which the elongate parts (13) extend, wherein the gel sealing block (5) comprises an upper flange (11) and a lower flange (12) with a support section (11a, 12a, 12b) disposed therebetween. The upper and lower flanges (11, 12) sandwiches in direction of extension of the elongate parts (13), a gel inner ring (7) supported by said support section (2) and a gel outer ring (6, 10a) covering the gel inner ring (7) in a radial direction extending transverse to said extension direction. The gel inner ring (7) and the gel outer ring (6, 10a) are made of a gel sealing material, wherein the sealing section (22) is formed therebetween. The gel sealing block (5) is adapted to seal in the sealing section (22) a tube end of at least one tube (14) guiding at least one of the elongate parts.