Custom adapters to allow you use a 1" threaded "road bike" headset with an old school BMX frame. These cups will allow you to use either a ISO headset (30.2mm cups) or JIS headset (30.0mm cups) on an old school 1" threaded BMX frame (32.5mm inner diameter headtube) The O.D. of the adapter cups is 32.5mm. Some frames are sized 32.7mm so these may slide in easily, but once the fork and headset is installed there will be no play. The I.D. of the adapter cups is 30.2mm, so for a JIS headset (30.0mm) the cups will slide in easily, but once the fork and headset is installed, there will be no play. NOTE: Each cup has a 2mm lip so these cups add 4mm to your headset's stack height. Material: 6061 aluminum alloy Color: BLACK ANODIZED SOLD IN PAIRS