A device for connection to a medical connector, the device comprising: a cap (102, 202) comprising an integral body (104, 204), a closed end (106, 206), an annular wall (108, 208) having a length L C extending from the closed end (106, 206) to an open end (110, 210) and defining a chamber (112, 212) containing an absorbent material (114, 214) and disinfectant or antimicrobial agent, the open end (110, 210) defining an end face (116, 216) and having a peripheral ledge (118, 218) extending radially inward from the annular wall (108, 208), the open end (110, 210) defining an engagement surface (120, 220); the annular wall (108, 208) having an exterior wall surface (122, 222) and an interior wall surface (124, 224); a peelable seal on the end face (116, 216) to prevent the disinfectant or the antimicrobial agent from exiting the chamber (112, 212); and an elastic sealing ring (126, 226); the device being characterized by: the elastic sealing ring having a dilatable opening (128, 228) therethrough sized and adapted to receive a male luer, a female luer connector and a hemodialysis connector, the dilatable opening (128, 228) sized to frictionally engage the male luer connector; the interior wall surface (124, 224) comprising internal threads (130, 230) adjacent to the closed end (106, 206), the internal threads (130, 230) 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 (128, 228), the absorbent material (114, 214) 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 (102, 202) comprising an integral body (104, 204), a closed end (106, 206), an annular wall (108, 208) having a length L C extending from the closed end (106, 206) to an open end (110, 210) and defining a chamber (112, 212) containing an absorbent material (114, 214) and disinfectant or antimicrobial agent, the open end (110, 210) defining an end face (116, 216) and having a peripheral ledge (118, 218) extending radially inward from the annular wall (108, 208), the open end (110, 210) defining an engagement surface (120, 220); the annular wall (108, 208) having an exterior wall surface (122, 222) and an interior wall surface (124, 224); a peelable seal on the end face (116, 216) to prevent the disinfectant or the antimicrobial agent from exiting the chamber (112, 212); and an elastic sealing ring (126, 226); the device being characterized by: the elastic sealing ring having a dilatable opening (128, 228) therethrough sized and adapted to receive a male luer, a female luer connector and a hemodialysis connector, the dilatable opening (128, 228) sized to frictionally engage the male luer connector; the interior wall surface (124, 224) comprising internal threads (130, 230) adjacent to the closed end (106, 206), the internal threads (130, 230) 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 (128, 228), the absorbent material (114, 214) 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 (128, 228) therethrough sized and adapted to receive a male luer, a female luer connector and a hemodialysis connector, the dilatable opening (128, 228) sized to frictionally engage the male luer connector; the interior wall surface (124, 224) comprising internal threads (130, 230) adjacent to the closed end (106, 206), the internal threads (130, 230) 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 (128, 228), the absorbent material (114, 214) and the disinfectant or the antimicrobial agent contact the said male luer connector, the said female luer connector and the said hemodialysis connector.