1.5" Threaded/Slip Bulkhead Twin Pack. For aquariums and filtration sumps. Manufactured with precision for smooth tightening. 2 Pack Threaded x Slip 1.5" Bulkhead. Stock color is jet black to match acrylic tank backgrounds. All kits contain: bulkhead fitting, gasket, lock nut. 2" 1/2" Hole diameter required. Heavy duty bulkhead is molded of highest impact resistant PVC eliminating possibility of finding hidden cracks when filling aquarium