Metal and mono-filament wire frame Accommodates a range of corrections to +2 to -7 Wire frame prescription carrier includes Advancer goggle hanger & Crossbow/Crosshair/ICE/ICE NARO compatable nosepiece. The ESS Vice Rx Lens Insert features a metal and mono-filament frame. The end result is a lightweight, low-profile prescription integration that is compatible with numerous ESS ballistic eyeshields. The Vice Rx Lens Insert accommodates a range of corrections to +2 to -7.