Based on my experience, this electrical assortment lives up TO its industrial and scientific categorization... it's an excellent collection with a wide range of sizes and types of connectors, which makes it extremely convenient and time-efficient. The connectors are made of high-quality materials that provide durability and long-lasting use. The only con I've noticed is that the connectors are not organized efficiently within the storage case. However, once sorted this set will definitely make a valuable asset for anyone who needs a variety of connectors..