Kinda bummed that your Vortex Solo 10x36 monocular didn't come with any lens caps? Well I've got you and your glass covered! This is a protective cover for both the eyepiece and the objective lens. They need to be printed from TPU or similar flexible filament. The eyepiece cap has a loop that the lanyard strap will fit through and the objective lens cap also has a hole through the “knob” so you can attach it as well. The eyepiece can be printed easily without support but the objective cap needs normal support as it is printed with the knob facing up.