Sig P320 Grip Modules allow you to easily change the look and feel of your P320 handgun. Simply drop in your P320 Fire Control Unit (FCU) and install the proper slide assembly. P320 grip modules come in 3 different girth sizes (Small, Medium, Large) and specific to different slide lengths (Compact/Carry and Full Size). This Medium Full Size X-Series Grip Module Assembly fits P320 models in 9mm, 357 Sig and 40 S&W and comes with the extended beavertail of the X-Series.