This Rothenberger Monoblock Tap Spanner Set features a one-piece steel construction with a zinc-plated finish for rust resistance. The set includes three heavy-duty, double-ended spanners that fit 8mm x 9mm, 10mm x 11mm, and 12mm x 13mm securing nuts commonly found on monoblock sink taps. A tommy bar is also supplied, which can be inserted into the spanners for increased leverage, and the spanners can be linked together to extend their length. These slimline tools are designed to make installation and removal of tap securing nuts easier, especially in confined spaces behind sinks and basins. They are ideal for tightening fixtures that have gone out of alignment.