From Park Tools:

"Thank you for using our products and your inquiry.
You may choose to use your SR-1 on your 11 speed cassette if you desire…please check to be sure it fits correctly.
Bicycle chain is all ½” pitch…meaning that there is ½” distance center to center of the rivets.
The teeth on a 5-6-7-8-9-10-11 speed chain are all the same distance apart so yes, the chain on your SR-1 will fit the individual sprockets, however…
On 11-speed systems the sprockets are placed much closer together to allow more sprockets to be placed in the same amount of space on the wheel.
When wider chain is used on a sprocket in the middle of these cassettes, the next smaller sprocket may keep the chain from fully engaging the teeth.
The wider chain used on the SR-1 should be used on the largest sprocket so that it completely grips the teeth.
Our chain whips use the same main body, with different size chains.
I trust this helps.
Please let us know if you have any other questions.
Thanks again"