Just dip an AquaChek Select test strip in your in your spa or swimming pool for fifteen seconds and remove it immediately. You will get your test results immediately! Test your spa, hot tub, or swimming pool a minimum of twice a week. An AquaChek Select Refill Bottle of 50 test strips, plus a new insert for the reusable color comparator is also available! The Select Kit includes a 24-page Pool and Spa Care and Treatment Guide with test log, 50 test strips and a reusable plastic color comparator.