Next-generation impact and crush resistant polymer construction; Designed specifically for Mil-issue Steyr AUG, F88 Austeyr, and F90*; Modified dimensions provide a slimmer footprint than factory Steyr magazines; Constant-curve internal geometry for smooth feeding; Anti-tilt, self-lubricating follower for increased reliability; Long life USGI-spec stainless steel spring, black-oxide coated (MIL-DTL-13924D); Anti-glare translucent MagLevel windows on both sides of the body along with a painted indicator on the spring allows for easy determination of rounds remaining from 1 to 30; Over-travel insertion stop on the spine; Ribbed gripping surface and aggressive front and rear texture for positive magazine handling; Paint pen dot matrix panels on the bottom of the body to allow for identification marking