The OSS kit is two-part user level modular upgrade for the PVS-14 format monocular. No modification to the legacy monocular, special tools or training are required for an OSS upgrade which takes minutes. The OSS upgrade maximizes interface options for virtually any standard dovetail receiver allowing matrix level interchangeability between optics and components. Included in the kit are both a top oriented helmet shoe which secures via a patented collar system and a bottom-oriented weapon shoe which affixes directly to the resident 1/4”- 20 standard receiver. Either or both shoes may be used for obverse mounting on a single monocular or the kit may be split between separate monoculars. The matched height/offset of the shoes allows adaptability in several configurations.