If the bubble level on your TRUGLO archery sight has fallen off the re-installation of the level is a straight forward process. If you were unable to locate the level or it was somehow damaged be sure to contact us for a replacement via the "Contact" link at the bottom of this page. If your bubble level attaches via a mounting plate at the bottom of the aperture any good quality clear household adhesive is fine. A clear, 5-minute two part epoxy is very good for this application. The mounting plate will already be level in the aperture so be sure the level sits flush against the plate and you're back in business.
One thing to note is if you have one of our Range Rover Series sights where the bubble level in contained within a bracket which is mounted below the aperture, the re-installation can be tricky but not impossible. However, if you should require assistance be sure to contact us using the "Contact" link at the bottom of the page and we'll be happy to assist you.