TR Fastenings' range of blind rivet nuts includes reduced head open end knurled body (imperial hole, reduced head open end plain body (imperial hole), reduced head open end hexagon body (imperial hole), reduced head open end knurled body. Dimensions are provided.
Study finds rooftop solar can deliver bulk of global electricity
...and at night or in long periods of overcast gloom similar to that which prevailed for much of this winter??