This product is intended for use with our range of loco frame etches. The width of the jig turnings is matched to the fold-up spacers supplied in the loco frame pack, and also available as a separate pack code LS15. These products can also be used to assemble loco frames of other manufacture. Used as directed, the jig will ensure that the frames are consistently assembled straight and square. You will also need a pack of LS59 adaptors if fitting sprung hornblocks to your frames.