channel 32 b 34 b for receiving the location boss 16 a when the sleeve portions 28 30 are positioned at the connector and tube assembly the location boss 16 a when aligned with and received in the recesses 32 b 34 b of sleeve portions 28 30 functions to locate the sleeve 18 and sleeve portions 28 30 at the connector 16 to generally align the recesses 32 a 34 a with the barbs so that the inner surfaces or profiles 32 34 are generally aligned with the form or shape of the connector 16 and further functions to align the threaded portions of the sleeve portions with one another so that the threaded fasteners may threadedly engage the assembled sleeve as discussed below the outer surface 36 38 of each sleeve portion 28 30 comprises opposite ramped or tapered or partial conical shaped ends 36 a 38 a with a center portion 36 b 38 b and threaded portions 36 c 38 c optionally the central portions 36 b 38 b may comprise a respective portion of a hexagonal shaped fastener or cross section such that the central region having a generally hexagonal shaped cross section can be engaged by a wrench to hold the sleeve and connector and tubes while another wrench tightens the fastener or fasteners as discussed below although shown as having a diameter that generally corresponds with the diameter of the threaded portions of the assembled sleeve the central portion of the sleeve may.