other words the oppositely facing parallel clamping surfaces are provided by the inner face of the clamping plate 16 and the inner face of the spacing arms 20 in fig1 the inner face of the thin portion 38 in fig2 and 5 and the inner face of the thick portion 40 in fig3 and 6 the use of the spacer 12 in conjunction with the screw 14 allows the screw 14 to be of a shorter length than if the spacer assembly was not available in other words for the clamp 10 to clamp to a thin item the screw 14 only needs to be of sufficient length to travel the distance x 3 depicted in fig3 rather than the longer distance x 1 depicted in fig1 in some embodiments the travel of the screw 14 is u215c inches other embodiments of the invention will now be discussed the further embodiments will be discussed only to the extent that they differ from the embodiments of fig1 to 6 like reference characters will be used for the same parts and the same parts will not be described in detail fig7 and fig8 a to 8d show a different spacer assembly which can be used with the clamp body 18 described with respect to fig1 to 6 a spacer 44 has the same basic configuration as the spacer 12 in particular the spacer 44 has a thin portion 46 connected to a thick.