Many thanks ladies for your input. Have just checked my ruler collection and yes, I found another one marked Rec Tool. (Pity though both pieces were not marked Tri Rec tool 1 & 2, at least one would then expect two pieces). I'll just have to put down my stupidity to getting older, dementia or senility. At least I won't have to embarrass myself at the lqs. Now will have to tie or pack them together so I don't get confused again.