[size=2]and they dont make a lot of electricity ball bearings because they only convert a very low % of sunlight into electricity. But these days they are getting better roller bearings.anyway. i wouldnt recommend installing needle bearings these in your home as they are quite expensive and not ver efficient fag bearings except in large numbers.hope this helps.wish i could post a picture but dont know how and dont know if fag transmission bearing its possible. =P[/size]