Click to expand Tap to zoom KWA I-37 LM4 & AKG Output Valve by KWA Save Liquid error (snippets/product-badge line 32): Computation results in '-Infinity'% $19.99 SKU 199-9999-I037 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart The KWA I-37 gas blowback rifle gas release valve fits all LM4 magazines as well as all AKG series magazines.