An optical adaptor for mounting to a receptacle to optically couple connectorized optical cables, comprising: - a coupling element to provide a passageway for inserting a ferrule of a first optical connector to terminate a first one of the connectorized optical cables and a ferrule of a second optical connector to terminate a second one of the connectorized optical cables to optically couple the first and the second connectorized optical cable (1, 2), the coupling element being configured to be insertable in the receptacle, - a mounting element to mount the first optical connector to the receptacle, the mounting element being configured to be insertable in the receptacle, - a fixing element to fix the mounting element to the receptacle, - wherein the mounting element is formed as a hollow body to receive the coupling element and configured to fix the coupling element to the receptacle, when the coupling element is inserted in the receptacle and the mounting element is fixed to the receptacle, - wherein the mounting element is configured to mechanically couple the first optical connector to the mounting element so that the ferrule of the first optical connector intrudes in the passageway of the coupling element at a first side (S110a) of the coupling element, - wherein the hollow body of the mounting element has a first side (S120a) with an opening to receive the first optical connector in the hollow body and a second side (S120b) to receive the coupling element, - wherein the mounting element comprises a first alignment element extending from the opening at the first side (S120a) of the mounting element into the hollow body of the mounting element, - wherein the first alignment element of the mounting element is configured to engage in an alignment element of the first optical connector to direct the insertion of the first optical connector to the mounting element, - wherein the coupling element has a second side (S110b) to insert the second optical connector into the coupling element to mechanically couple the second optical connector to the coupling element such that the ferrule of the second optical connector intrudes in the passageway of the coupling element, - wherein the fixing element comprises a hollow screw to fix the mounting element to the receptacle, - wherein the mounting element and the hollow screw are configured such that the hollow screw is slideable on the mounting element from the second side (S 120b) of the mounting element and is rotatable on the mounting element. - a coupling element to provide a passageway for inserting a ferrule of a first optical connector to terminate a first one of the connectorized optical cables and a ferrule of a second optical connector to terminate a second one of the connectorized optical cables to optically couple the first and the second connectorized optical cable (1, 2), the coupling element being configured to be insertable in the receptacle, - a mounting element to mount the first optical connector to the receptacle, the mounting element being configured to be insertable in the receptacle, - a fixing element to fix the mounting element to the receptacle, - wherein the mounting element is formed as a hollow body to receive the coupling element and configured to fix the coupling element to the receptacle, when the coupling element is inserted in the receptacle and the mounting element is fixed to the receptacle, - wherein the mounting element is configured to mechanically couple the first optical connector to the mounting element so that the ferrule of the first optical connector intrudes in the passageway of the coupling element at a first side (S110a) of the coupling element, - wherein the hollow body of the mounting element has a first side (S120a) with an opening to receive the first optical connector in the hollow body and a second side (S120b) to receive the coupling element, - wherein the mounting element comprises a first alignment element extending from the opening at the first side (S120a) of the mounting element into the hollow body of the mounting element, - wherein the first alignment element of the mounting element is configured to engage in an alignment element of the first optical connector to direct the insertion of the first optical connector to the mounting element, - wherein the coupling element has a second side (S110b) to insert the second optical connector into the coupling element to mechanically couple the second optical connector to the coupling element such that the ferrule of the second optical connector intrudes in the passageway of the coupling element, - wherein the fixing element comprises a hollow screw to fix the mounting element to the receptacle, - wherein the mounting element and the hollow screw are configured such that the hollow screw is slideable on the mounting element from the second side (S 120b) of the mounting element and is rotatable on the mounting element.