I've just bought this dust, as the previous speaker then showed that it fits in its Tastur (G15). And he's right! The size of the dust cover is sufficient for exactly one Logitech G15 refresh. Otherwise, the part does what it is, it protects against dust ;-)
+++ 18.06.2012 +++ UPDATE Fits also on the Logitech G510 serving as the G15 is slightly larger refresh. However, the shell sits quite tight here. But I use them still, because they still served their purpose.