The Vortex Precision Diving Board Mounts easily mounts to their Precision Matched Riflescope Rings to give you an elevated and extended platform for mounting the Impact 4000 Ballistic Rail-Mounted Laser Rangefinder. These diving board mounts take the place of your front ring cap. Machined from 7075-T6 aluminum and Type III Hardcoat Anodized, these mounts will stand up to some punishment. Available for 30mm or 34mm tube diameters. Mfg: Vortex Optics