I actually was given one of these by a friend prior to me receiving my bike. When it came i had already purchased the 2 separate pieces rather than the combined unit.
I actually sold it to a member on here who said he was very please with it, and was a great ft for his F4.
Just be careful of the quality on Ebay.
yeah i have one. There are two types, one which you have to actually drill into the swing-arm to fit onto the earlier models, or the ones like shown that use an expanding rubber nut into the hole for the rear shock. the second type (what i have) always feel a little loose and sit very close to the wheel. we actually had to put a spacer in mine so that it sits a little off center but further away from the wheel so it doesn't rub.
also may lead to the carbon flu. symptoms consist of a light wallet and angry wife / other-half...