vivitar extension tubes for nikon

[Baddgsx]

http://www.bhphotovideo.com/c/product/794151-REG/Vivitar_VIV_EXT_N_Macro_Extension_Tube_Set.html



can someone tell me if these are the correct extension tubes for nikon f-mount ai-s lenses. It doent say f mount on the specifications.

thanks,
Chris