Custom installations are easier and safer with all parts included in convenient kits. Heavy wall bulkhead is molded of highest impact resistant PVC eliminating possibility of finding hidden cracks when filling aquarium. LIFEGARD® Multi-Purpose Bulkhead Fittings -Stock color is jet black to match acrylic tank backgrounds. -All kits contain: bulkhead fitting, gasket & lock nut Specifications - Flange Side: Threaded - Bottom Side: Threaded - Hole Size Required: 1.673"