Hexatronic FCLDXHDCKITCCSO4X7 (Millennium part 551327) is a mechanical compression seal cable entry kit for four cables of 4 to 7 mm outside diameter, used with Hexatronic dome closures in outside plant. Mechanical compression means the seal is made by torquing hardware rather than heat-shrinking, so a technician can open, re-enter and reseal the closure repeatedly without a torch or replacement sleeve. That reusability is decisive in FTTH distribution closures that get revisited every time a new drop is added. Matching cable OD to the correct seal range is what keeps the enclosure watertight.