The Sunday BMX integrated headset is designed to be a quality headset at an affordable price. It offers one of the lower stack heights on the market. It's Campagnolo standard spec. 1-1/8 integrated headset. 45Î_ tapered bearings with 41.8mm outer diameter to fit 42mm BMX head tubes. Compatible with Odyssey GTX Gyro, GTX-R, GTX-S and Snafu Mobeus. 1-1/8. Comes with matching 3mm and 5mm spacers.