XS Sight Systems 24/7 Big Dot Tritium Sight Glk 20,29,21,30,37,38,39 Green/Green 2 Dot GL-0002S5. Note: Please check your state regulations, hunting regulations, etc before placing an order for any of our items. Your order may be canceled if the item is not able to be shipped to your state due to their regulations. The product is manufactured by XS Sight Systems using Trijicon parts.