LS5 - ACI File-To-Fit may be required as

File-To-Fit may be required as each MP5 is individually welded

5 M-LOK™ slots

please be sure to add our Atrius Compatibility Insert to your order

preventing hammer override

Geissele triggers will come modified

LS5 - ACI File-To-Fit may be required asThe LS5 ACI is an insert that goes in a Lee Sporting LS5 Trigger Housing. It's function is to maintain compatibility between the LS5 and Atrius FRS by preventing the Atrius's lever from falling out of reach of the slip trip. It is made from a durable polyurethane in the USA. The LS5 ACI should be placed inside your LS5 Housing before the FRS. Insert the LS5 ACI in the rear of the trigger pocket. Please note, a slip trip is required to activate the