Dear Customer, so sorry to tell you that this adapter won't allow your nikon 1 s1 lenses to mount to my canon t2i. 

Yes, please check the size of the camera lens thread before purchasing. 

67mm should also be stenciled on the front edge of the lens somewhere. If so, then you should be good to go. It should be on the lens because a lens cap can be lost or broken. 

FD-EOS fit for Canon FD mount lens and canon EF mount camera body. canon 60d is EF mount, so the adapter ring can work with your camera, but you need to check your lens mount. could you pls let us know your lens specific model? service(AT)kentfaith(DO NOT)com, Please note: It is not same between Canon FD mount and EF mount, this adapter ring is only for Canon FD mount lens, please contact us if you want to purchase for Canon EF mount lens. 

Yes. This product is designed for crop sensors. They work great on my T3i worth the buy.