Verified Buyer Reviewed by Schatzie from Arkansas on Thursday, March 22, 2018I bought 2 of these for my 76 y.o. mother. The doctor told her she must drink more water. Since receiving these cups, she has increased her water intake, and her kidney function test are in normal range again. She states that for some reason she will drink more if she has a straw. This seems to work for her, so I am all for keeping her healthy. Thanks Sierra Trading Post!