to an underlying surface e g the above described inner surface of a steel tower section wall thereby establishing attachment by normal forces between the underlying surface and the tube 41 moreover it should be noted that the fitting facilitates a degree of tolerance in the direction of the illustrated arrow between the fitting 42 and the bolt 22 of the suspension unit 20 the freedom of tolerance provides a certain degree of tolerance when attaching the suspension units 20 to a tower in the manner suggested by the invention the illustrated suspension unit 60 comprises a main body 61 and two bolts 62 basically the illustrated suspension unit 60 is constructed according to the principles outlined in the single bolt version of the unit in fig2 b fig5 b illustrates the fitting of e g a steel bar 65 to the suspension unit 60 the steel bar 65 is mechanically fixated to the suspension unit 60 by means of a suitable fitting 66 by means of nuts not shown it should be noted that the illustrated assembly features a certain degree of tolerance in both the u201c vertical u201d and u201c horizontal u201d directions as illustrated by the arrows fig6 a and 6b illustrate a method of mounting a suspension unit 60 according to the invention to a magnetic surface not shown e g a steel wind turbine tower initially in fig6 a a suspension unit is arranged on e g a steel surface a nylon sheet 65 is located between the underlying surface and the suspension unit 60 due to the thickness of the sheet and the relatively low friction the suspension unit 60 and.