The table below indicates the assembled stud centres in a panel then section x gauge and then the product reference

Lattice Beams 65mm x 1.2mm  
Lattices 225 L225-6512
Lattices 300 L300-6512
Lattices 350 L350-6512
Lattices 400 L400-6512
Lattices 450 L450-6512
Lattices 500 L500-6512
Lattices 550 L550-6512
Lattices 600 L600-6512
Lattice Beams 100mmx 1.2mm  
Lattices 225 L225-10012
Lattices 300 L300-10012
Lattices 350 L350-10012
Lattices 400 L400-10012
Lattices 450 L450-10012
Lattices 500 L500-10012
Lattices 550 L550-10012
Lattices 600 L600-10012
Lattice Beams 100mmx 1.6mm  
Lattices 225 L225-10016
Lattices 300 L300-10016
Lattices 350 L350-10016
Lattices 400 L400-10016
Lattices 450 L450-10016
Lattices 500 L500-10016
Lattices 550 L550-10016
Lattices 600 L600-10016
Lattice Beam 150mmx 1.6mm  
Lattices 225 L225-15016
Lattices 300 L300-15016
Lattices 350 L350-15016
Lattices 400 L400-15016
Lattices 450 L450-15016
Lattices 500 L500-15016
Lattices 550 L550-15016
Lattices 600 L600-15016