HIPERFIRE AK Main Spring Black. Our new mainspring is a tri-twist music wire AK mainspring that provides a 2+ pound pull weight and a hard positive reset on our popular XAK series triggers. Our XAK Mainspring is compatible with our XAK line of triggers as well as other stock and aftermarket AK fire controls. NOTE: Pull weight and feel may vary from receiver-to-receiver and trigger-to-trigger as there is no "mil-spec" standard for all AK platforms. At HIPERFIRE we do our best to be as open and deliberate as possible with the information we put out. Stated pull weights are true with the combination of HIPERFIRE XAK triggers and XAK Mainsprings. We cannot guarantee pull weights in other configurations using triggers or mainsprings from other brands. Specifications for HIPERFIRE AK Main Spring: Manufacturer: HIPERFIRE Color: Silver Gun Model: AK-47 Gun Type: Rifle Features of HIPERFIRE AK Pins: Chamfered edges for easy push-through installation Package Contents: HIPERFIRE AK Main Spring What firearm models does the manufacturer say HIPERFIRE AK Main Spring is compatible with? The manufacturer suggests that HIPERFIRE AK Main Spring is compatible with AK-47HIPERFIRE XAKMS: AK Main Spring Black