This rubber hole plug fits the bill for all my industrial needs. According to my experience, it is durable and well-made, and fits securely into any opening .The material is of high quality and can withstand heavy usage. As a bonus it offers good protection against dust and debris. The only downside is that it can be a bit tricky to insert into smaller openings, but this is a minor issue. Overall, a great industrial and scientific product that i would highly recommend..