Here is a review left by a customer on a product. Would you say he was satisfied or dissatisfied?
Title: Save your money
Review: I bought these with new bowls that had holes for sight plugs hoping to correct the bowl fuel level problem i've been fighting with. After i put them in, i realized that i couldn't see much through them. After installing the carb, it was a few days until i was ready to start the engine. In that time we had a string of cold nights and warm days. When i checked everything before the first start, i found that these had broken off in the holes, leaving the threads in place and the "heads" and o-rings sitting on my intake. Now i have to pull the bowls off and drill/tap the plug holes to remove the plastic. I don't recommend these even if you won't use them in extreme temperature changes, because they didn't appear to be very see-through when they were whole. Save your money and time and buy the metal ones.
