Nobody makes 1" threadless stems anymore and finding a good used one is damn near impossible.

This premium quality aluminum shim allows the use of 1-1/8" threadless stems on 1" threadless forks.

Stack height is 37mm and will work on any 1 1/8" threadless stem (not just Thomson).

FYI: When using a 1 1/8" stem and shim on a 1" steerer, you need to use a 1 1/8" top cap. If you’re putting any headset stack spacers beneath your stem, you’ll need to use 1” spacers.