DON'T SEND A BOY... TO DO A MAN'S JOB.
(common saying in the game of euchre.)
If you are a card player, euchre to be specific you may hear this said by your opponent when you send a 9 or a 10 of suit while you were clutching onto a Queen, King, Ace, or dare I say trump and subsequently lost the trick. Well, interestingly the same concept applies to weep hole covers. If you set yourself up with the wrong product, the wrong material or the wrong air ventilation, you are virtually sending a boy to do a man's job and you are going to be disappointed.
I'm no different than you, when I can save a buck, I'm the first in line even though I know I get what I pay for. Sometimes though, what we pay for isn't meant for the job in the first place and this is where I challenge you to consider your options.
Why are you interested in Weep Hole Covers? Mice? This is usually the case.
So, we want to stop them from getting into our houses, spreading disease, destruction and god forbid chewing up the electrical wiring which they love to sharpen their teeth on. I can't be certain, but the tingle they get from the live wire must be the equivalent of an addiction to something like sniffing glue or gasoline. I digress.
Now imagine, your young son or daughter comes to you interested in a new hobby. They want to enjoy mice in a cage as pets in their bedroom in...your home. You oblige and go to the store to buy the housing and supplies. What comes to mind - a plastic wire cage or a metal wire cage. If you said metal your life will be much easier. See, mice are olympic chewers and anything you put infront of them that they can chew, they will chew through. So plastic isn't helpful, get the picture?
So back to weep hole covers. Other than the fact mice will chew through plastic material there is another not so apparant problem overlooked by the manufacturers, resellers and home owners who deal in plastic weep hole covers. See mice leave pheromone trails everywhere they go, we can't see them but they are there. The important thing is, mice immediately detect them and follow them becuase it takes them to other mice for possible mating, food sources and shelter.
Studies have shown if a male mouse detects a female mouse is or has been on the other side of a plastic weep hole cover, the result is predictable. The weep hole cover loses every time hands down.
So you have a decision to make. Are you willing to bet mice won't chew through your weep hole cover or do you want to arm your house, your largest investment, with the device that was actually designed with the real science behind mice and their true capabilities in mind.
Some final thoughts, we don't go to zoos with tigers in card board boxes, we don't fly at 30,000 feet without a reinforced pressurized cabin, nor do we drive around in bullet proof cars which is overkill for the job at hand. I hope you see now that stainless steel weep hole covers are not overkill and plastic is not suitable for the job. Infact the only solution that should ever enter your weep holes are Stainless covers designed to allow the wall cavity to breath as intended by building codes. The few extra bucks you spend, if at all, reward you for a long time to come.