Sig Sauer Mainspring Seat, P220/6/9 $12.50 Plastic Mainspring Seat, P220, P226, P229. Factory replacement mainspring seat, Sig Part: Mainspring-seat-1 Out of stock Category: Sig Sauer Related products Sig Sauer P220 / P226 Variable Recoil Spring 20lb. $14.97 Sig Sauer P220 – 29 Reduced Power Hammer Spring Pak, for plastic spring base $24.97