You can thank Campagnolo for the Italian integrated standard. It's slightly different than Cane Creek's IS (international standard) integrated headset sizing. We like to remember the Italian sizing like this -- the headtube has a 42mm i.d and Mario Cipollini, a notable Italian bike racer, won a record 42 stages in the Giro d'Italia, a notable Italian bike race. The 40-Series Integrated IS42 IS42/30 Italian Standard Headset is Cane Creek's best offering with regards to blending smooth performance, durability, and value.
This 40-Series Headset spins on Cane Creek's black oxide bearings. The races and balls start out as 52100 steel and are then given an acid bath to make them more corrosion resistant, while still being porous enough to retain grease. They are angular contact bearings (ACB), which resist both axial and radial loads equally well. The cartridges are sealed with what Cane Creek likes to call a Split Lip Seal, which has two contact seals per side to better keep out contaminants and hold in grease. To augment the seals on the cartridge bearings, Cane Creek adds face seals to the crown race and top assembly. So what if the bearings aren't stainless -- grease kept in and muddy goop kept out keeps 'em running like new for a long time.
In the event that you might wreck the bearings through normal use or abuse, you should know that all the internal parts in this 40-Series Headset are compatible with their top-of-the-line 110-Series Headset. So you could always upgrade to the 110 headset's stainless steel bearings. The Clip-Seal in the upper assembly holds all the parts together, including the compression ring. This makes assembly a cinch, since there are no loose parts to misplace or install backwards.
The Cane Creek 40-Series Integrated IS42 IS42/30 Italian Standard Headset has a top bearing cover that's CNC machined from 6061 T6 aluminum, and it's polished and anodized Black. Cane Creek adds laser etched graphics to the top cover, including their Skink logo. This is an integrated headset that will mate a fork with a straight 1-1/8in steerer tube to a 1-1/8in Italian standard head tube having a 42mm i.d. The top bearing cover is compatible with Cane Creek Interlok spacers. The stack height for the top bearing cover assembly is 15mm and the bottom is a mere 1mm.