these are iscreen specimen validty test strips i purchased off of amazon. i've used them to test two samples of quickfix 5.7 bottles and the abnormal oxidant/pcc did not show up. the lady on the phone tried to reassure me the urine would work even if my strips said there was something off. she ended up saying that she had opened up a bottle of quickfix yesterday to test( i guess for drugs?) and she would send it to me tomorrow but i wouldn't be recieving a box. I was like kinda like uh can't i just send the lil whizz back to you and you send me a bottle of QF considering that is what i ordered but she said that i could just keep the lil whizz and i gave up talking sense to her. I feel its kinda fishy getting an opened bottle of QF but if that passes the validity test it should be okay to use?