Whats The deal with aftermarket handlebar end caps

I bought some end caps for my cbr 1000 because they were a different color. Well they have arrived and they are lighter in weight than the original ones. Is there
a reason the Honda Stock Caps are heavier? Has this got to do with balancing the handle bars or sterring stabilizer? Is there a danger using the aftermarket ones?
 
Does anyone know?
 
Thanks
 
Todd

Its more for reducing vibration in the handle bars. The heavier bar ends tend to reduce vibrition more as oppose to the lighter ones. As long as you like them thats all that matters; there's no danger what so ever with using aftermarket ones.