Sentence:  He also bought a huge square of pegboard for hanging up his tools , and lumber for his workbench , sandpaper and glue and assorted nails , levels and T squares and plumb lines and several <WSD>gadgets</WSD> that he had no idea how to use or what they were for . 
Meaning of the word marked with <WSD> tags:  a device or control that is very useful for a particular job