I thought I did it right but no. I forgot to put a 2nd hole to relive pressure in the cap. Plus i think the blood pressure cuff was too tight. TB-500 put me to 60% and I was already around 56 giving blood every 8 weeks. I'm so freaking tired I cant wait until next week to give blood again. I gave last week to red cross and I'm ellgible next week at community blood. Community freaks out when hemo is over 18 and red cross won't take it at all when hemo is over 20 or hematocrit 60. I'm going to try again tonight or tomorrow. Ive read all the bass posts on it and still can't get it to go.