#html-body [data-pb-style=TGCCXQH]{justify-content:center;display:flex;flex-direction:column;background-position:left top;background-size:cover;background-repeat:no-repeat;background-attachment:scroll}#html-body [data-pb-style=H4GWBVX],#html-body [data-pb-style=TGCCXQH]{border-style:none;border-width:1px;border-radius:0;margin:0;padding:0}Factory replacement piston assembly 5.5 in for the SIG MCX 300 BLKInstallation of these parts kits requires disassembly of your firearm beyond a "field-stripped" condition. Improper installation may result in malfunction, serious injury, or death. SIG SAUER requires that only certified SIG SAUER armorers install these parts kits. Any damage caused by the incorrect installation of these parts kits is not covered by your firearm's warranty, and SIG SAUER will charge for any needed repairs to a firearm damaged by improper use or installation of these parts kits.WARNING: These parts kits are intended to be installed as a full unit. Any substitution of included parts may be incompatible and may lead to malfunction, serious injury, or death.