Leupold Alumina VX6 Flip Back Lens Cover, 56mm Flip Back design maintains a low profile in the field Compatible with VX-3, VX-3i, VX-5HD, VX-6, VX-6HD, and Mark 5HD riflescopes with 56mm Objective lenses Round design lets you rotate your Alumina VX6 and open the cover in any direction Many Leupold scopes built prior to 2004 can be threaded to accept Alumina accessories