Double Eagle M917c UTR45 SMG (Falcon EFCS - Black - M917c)
front to back
14mm neg thread 
polymer m lock front
quick change spring under the stock
fire unit trigger type progamable (mosfet)with pulls of trigger
sets trigger 1mm-3mm settings
fire on pull and release of trigger
1-5 shot burst instead of full auto
with full instructions
flip up sights
comes with 120rd midcap magazine
ambi fire select 
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battery goes in stock at back stock
deans connection
no battery or charger with gun 
advise a stick 1100 mah 11.1v stick lipo
this seams to fit nice
great rate of fire and even gives you 5 beeps at 3v 
so you can change out the battery
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this is one of our best selling bb guns at the present time