The Monument 3 Piece Mono Tap Back Nut Box Spanner Set is a specialist tool kit designed for efficient installation and removal of tap backnuts on basin installations. This double-ended spanner set provides plumbers and bathroom fitters with the essential sizes needed for modern mono tap assemblies, eliminating the need to purchase individual spanners or struggle with adjustable alternatives. The set includes three double-ended box spanners covering six common backnut sizes: 8 x 10mm, 9 x 11mm, and 12 x 13mm. This comprehensive range ensures compatibility with the majority of mono tap fittings encountered in domestic and light commercial plumbing work. The box spanner design provides a secure grip on backnuts in confined spaces beneath basins where standard spanners cannot reach. Each spanner in the Monument GRIP+ set is supplied with a T-bar that allows for comfortable leverage and improved torque application when tightening or loosening backnuts. This feature is particularly valuable