Hammond 1550Z Watertight IP66 Diecast Enclosures - Hammond 1550Z120, The Hammond Diecast Enclosure (Thick Wall, 171 x 121 x 55mm) Natural 1550Z120 is a thick walled diecast aluminium watertight enclosure with natural or black finish. O ring sealed, tongue and groove construction prevents ingress of dust and water into the enclosure and fixing screws outside the gasket area avoids the need for O rings on the screws. Hammond 1550Z120 Diecast Enclosure (Thick Wall, 171 x 121 x 55mm) Natural