Patent ID: 6872008

Claim:
An optical adapter, comprising: a split sleeve having a slit formed therein throughout the entire length in the longitudinal direction thereof and an adapter housing having a sleeve retaining part in which said sleeve is inserted and retained, wherein said sleeve retaining part is provided with an engagement comprising one of a recessed portion and a projected portion, said split sleeve is provided with a counter engagement part comprising the other of said recessed portion and said projected portion which engages with said one of the recessed portion and the projected portion of said engagement part, the recessed portion and the projected portion of the engagement part or counter engagement part have a width larger than the width of said slit of the split sleeve, and said split sleeve is a conversion sleeve comprising a large diameter part, a small diameter part, and a tapered diameter part interconnecting said two parts, said split sleeve being provided with an inwardly projected ferrule insertion stop part formed on one of an inner circumferential surface of said tapered diameter part and inner circumferential surfaces of the large diameter part and the small diameter part adjacent to said tapered diameter part.