searched but can't find anywhere or anyone who mentions their Kosei K1's offset

i've looked on the wheels thread and saw a couple guys with Kosei K1's mostly 17" from what i could tell, but no mention of offset anywhere.
The Kosei website doesn't mention it either.
How does this wheel clear big brakes? AP specifically...

 

Check Tirerack site. K1 TS +42mm.

Finish Shown: Light Grey Painted
Other Available Finishes:
Silver Painted
Orange Painted

Size Selected: 17x7
Price: $199 (each)
Estimated Availability: Low Stock
Recommended Tire Size: 205/45-17
Wheel Offset: +42mm
** Lightweight: 14.1 lbs. **

 

45

 

lol...so is it 42 or 45 or both?
is that the 17" offset?
do they make an 18" K1 and what would the offset be?
what's the ideal offset without rubbing (40 for 17" and 35 for 18" tire profiles)?

thanks.

 

Largest K1 is 17" and is a 45 offset. Min. offset depends on wheel width and what tires are being used. Others can answer that better then me.