Abstract: A device for froming a solder connection between a plurality of elongate bodies comprises a dimensionally recoverable article, e.g. a heat-shrinkable sleeve, into which the bodies can be inserted, and a solder insert. The solder insert comprises two portions, one formed from a relatively low melting point solder for forming a solder joint between the bodies, and the other portion being formed from a relatively high melting point solder. When the device is heated the relatively high melting point solder will not melt until the low melting point solder has melted and flowed, and therefore provides a means for indicating that the correct temperature has been reached.