Replacement Rubber Washer for 0.5″ Sch. 40 BulkheadReplacement Rubber Washer for 0.5″ Sch. 40 BulkheadRubber seal that makes a water tight seal when used with the appropriately sized bulkhead fititng. The rubber washer goes on the ‘wet’ side of the tank or resevoir.Rubber seal that makes a water tight seal when used with the appropriately sized bulkhead fititng. The rubber gasket goes on the ‘wet’ side of the tank or resevoir. – See more at: http://www.bigalspets.com/bulkhead-fitting-gasket-1.html#sthash.Wx9AAg9u.dpufRubber seal that makes a water tight seal when used with the appropriately sized bulkhead fititng. The rubber gasket goes on the ‘wet’ side of the tank or resevoir. – See more at: http://www.bigalspets.com/bulkhead-fitting-gasket-1.html#sthash.Wx9AAg9u.dpufProduct code: 3917Item No. PL-BHW-0.5