A device for connection to a medical connector, the device comprising: a cap comprising an integral body , a closed end , an annular wall having a length L C extending from the closed end to an open end and defining a chamber containing an absorbent material and disinfectant or antimicrobial agent, the open end defining an end face and having a peripheral ledge extending radially inward from the annular wall , the open end defining an engagement surface ; the annular wall having an exterior wall surface and an interior wall surface ; a peelable seal on the end face to prevent the disinfectant or the antimicrobial agent from exiting the chamber ; and an elastic sealing ring ; the device being characterized by : the elastic sealing ring having a dilatable opening therethrough sized and adapted to receive a male luer , a female luer connector and a hemodialysis connector , the dilatable opening sized to frictionally engage the male luer connector ; the interior wall surface comprising internal threads adjacent to the closed end , the internal threads adapted and sized to engage the said female luer connector , wherein when a said male luer connector , a said female luer connector and a said hemodialysis connector is inserted through the dilatable opening , the absorbent material and the disinfectant or the antimicrobial agent contact the said male luer connector , the said female luer connector and the said hemodialysis connector . a cap comprising an integral body , a closed end , an annular wall having a length L C extending from the closed end to an open end and defining a chamber containing an absorbent material and disinfectant or antimicrobial agent, the open end defining an end face and having a peripheral ledge extending radially inward from the annular wall , the open end defining an engagement surface ; the annular wall having an exterior wall surface and an interior wall surface ; a peelable seal on the end face to prevent the disinfectant or the antimicrobial agent from exiting the chamber ; and an elastic sealing ring ; the device being characterized by : the elastic sealing ring having a dilatable opening therethrough sized and adapted to receive a male luer , a female luer connector and a hemodialysis connector , the dilatable opening sized to frictionally engage the male luer connector ; the interior wall surface comprising internal threads adjacent to the closed end , the internal threads adapted and sized to engage the said female luer connector , wherein when a said male luer connector , a said female luer connector and a said hemodialysis connector is inserted through the dilatable opening , the absorbent material and the disinfectant or the antimicrobial agent contact the said male luer connector , the said female luer connector and the said hemodialysis connector . the elastic sealing ring having a dilatable opening therethrough sized and adapted to receive a male luer , a female luer connector and a hemodialysis connector , the dilatable opening sized to frictionally engage the male luer connector ; the interior wall surface comprising internal threads adjacent to the closed end , the internal threads adapted and sized to engage the said female luer connector , wherein when a said male luer connector , a said female luer connector and a said hemodialysis connector is inserted through the dilatable opening , the absorbent material and the disinfectant or the antimicrobial agent contact the said male luer connector , the said female luer connector and the said hemodialysis connector . <EOS>