Assembly with junctions without tools. Detachable junctions: Junctions in two  removable pieces with a closure for a ‘high clamping force on the convergence point up to 100 kg per junction. Small and aesthetic hole: differentiation compared to  the standard thanks to a minimum hole of 6 mm. Stowable: the pieces preassembled with P-System  junctions can be stowed for storage and transport. Only one tool: standard hex wrench 4 mm to lock the junction. Assembly tolerance: positioning pins with tolerance of +/- 1 mm for an easy assembly. Resistance to torsion: the positioning pins guarantee maximum resistance to torsion without additional elements.