Leapers UTG has designed the best polymer magazine that is guaranteed to feed and function flawlessly in your Glock handgun. UTG is known for its quality products and this magazine is no exception. This magazine has endured multiple tests; temperatures ranging from extreme heat to extreme cold, water, dirt, dust, drop and even a weight test. Yes, a weight test, drive your truck over it, pick it up and place it back in your handgun to continue shooting.