KM4-SR5 (http://www.kwa.com.hk/kwa_home/product/km4-sr5/) used but fully functional. Comes as part of a package including:
Batteries
Charger
Some BBs
Protective Glasses
3x Magazines
Cleaning Spring
Angled Foregrip
Working Holographic Sight
Speed-Loader
Paper Targets
Sling
Rifle Bag