If you are wanting something different, take a look at the reef octopus sch 80 bulkheads (They sell them on coralvue's website.) The 1" ones fit in the same size hole as the black abs/sch 40 ones. I switched to them because of the excellent seal they provide. Instead of the crappy washers like most bulkheads have, these use seated o-rings and are just a much better bulkhead overall, imo.