One Professional Teeth Whitening patient kit includes 10 trays, with 2 strips each - for the upper and lower arches - for 5 days of applications.
In most cases, teeth will brighten up to 5 shades whiter in just 5 days! Competitors require 10-14 days of applications.
The side facing up contains the whitening formula. (The white zig-zag seen below is not the whitening ingredient - it only holds the strip to the tray).