of giving it to another kid because of the mask? >> that's correct. that's the primary intervention. these schools didn't do widespread screening testing, they didn't do widespread ventilation changes. they simply had universal masking. they had very high compliance with that. we had substudies in several districts which showed a compliance rate greater than 90% in the mainstream curriculum and we're getting ready to submit that for publication later this month. but, yeah, the primary intervention masking. >> do you know what it would be without a mask, if a child with covid came to a location with covid but no mask, do you have a sense of what the likelihood of transmission would be? >> sure, the best data points that we have thus far are from israel back in 2020 where it was approximately 13 to 16% of the children and adults were