The Winged Eyecup/Rainguard Set by Swarovski fits NL Pure, EL, and SLC Binoculars.
I think winged eyecups improve the binocular experience enough that manufacturers should include them as standard equipment. Better yet design binoculars that include them as a basic element. I'd go so far as to say mediocre binoculars can be instantly upgraded to something much better by the addition of winged eyecups. Field Optical Research makes very nice ones that fit very nicely on my Vortex Razor UHD's, but not so much on my Swarovski NL Pure's. Thankfully these Swarovsky's do the job, and the included lens caps (rain guards) are an improvement over those that come with the NL Pure's by being much easier/quicker to remove for viewing.
These work as advertised. The take all the stray light from the sides out of your eye. I have these on both pairs of my Swarovski's. Wouldn't be without them for all hunting situations!