Constructed from next-generation impact and crush-resistant polymer, the magazine features durable, dual-side transparent windows which allow for a quick count of the approximate number of rounds remaining in the magazine via a high visibility indicator coil on the spring and numerical markers on the magazine body. This proprietary capability, known as the MagLevel system, provides a fast round-count estimation without affecting the durability or reliability of the magazine. Anti-tilt, Self-lubricating Follower Stainless-steel Spring for Longevity and Durability