Aluminum covered self-adhesive tape by Cezar is designed for joining underlays. It constitutes a vapour barrier and protects against infiltration of moisture.
Width of tape is 48mm. It is available in two lengths: 22m and 50m.
The film presenting correct laying of floor underlay with the use of Cezar products (vapor retarder film, underlays, aluminium tape) is available at: https://www.youtube.com/watch?v=T8q4s5GGcRI