HEADSET TYPE: Threadless Zero Stack Upper Cup & External Lower Cup
STEERER TUBE: Tapered 11/8" to 1.5"
MATERIAL: Alloy
STACK HEIGHT: 30.3mm
UPPER CUP: 44mm Flush Cup
LOWER CUP: 49mm External Cup
UPPER BEARING: 36° x 45° 11/8" ACB Sealed Bearing 41.0mm OD
LOWER BEARING: 36° x 45° 1.5" ACB Sealed Bearing 51.8mm OD

Not sure if this is the one you need?
Check out the handy FSA Headset ID Tool here http://www.fsaeasyheadset.com/