https://www.armsunlimited.com/Translucent-Polymer-AR15-M4-30-Round-Magazine-p/ets-ar15-30.htm
https://www.armsunlimited.com/Lancer-Translucent-223-556-AR15-M4-30rd-Magazine-p/l5awm-tl.htm
For that matter, they have 15, 17, or 31 round clear ETS Glock magazines for the same price.
https://www.armsunlimited.com/Translucent-Polymer-GLOCK-17-9mm-31-round-Magazine-p/ets-1831.htm
https://www.armsunlimited.com/Translucent-Polymer-GLOCK-19-9mm-15-round-Magazine-p/ets-1915.htm
https://www.armsunlimited.com/Translucent-Polymer-GLOCK-17-9mm-17-round-Magazine-p/ets-1717.htm
https://www.armsunlimited.com/Lancer-Translucent-223-556-AR15-M4-30rd-Magazine-p/l5awm-tl.htm
For that matter, they have 15, 17, or 31 round clear ETS Glock magazines for the same price.
https://www.armsunlimited.com/Translucent-Polymer-GLOCK-17-9mm-31-round-Magazine-p/ets-1831.htm
https://www.armsunlimited.com/Translucent-Polymer-GLOCK-19-9mm-15-round-Magazine-p/ets-1915.htm
https://www.armsunlimited.com/Translucent-Polymer-GLOCK-17-9mm-17-round-Magazine-p/ets-1717.htm