Name: BI-3981M
Manufacturer BOYI
Gun propulsion: electric - metal gearbox ver. 2
The replica is made of: ABS: buttstock, and RIS rails facings,
metal: body, external barrel, gas pipe imitation, RIS rails system, adjustable folding rear sight aperture, reload lever, Hop-Up chamber, sling swivel, magazine, and buttstock extension buffer tube.
Velocity (FPS): 350 fps
Magazine/Clip Capacity: 300 BB's (HI CAP magazine)
Gun lenght: 71,2-79,4 cm
Gun weight: 3500 g

The replica has also an adjustable Hop-Up, which can be reached by pulling back the reload lever. The reload lever opens ejection port cover, where the Hop-Up control is located.
In a gear box of this model there are 7mm bearings. The place for battery is in a buttstock (SF type). Thanks to it, we gain a better balance of the replica.
 

Additional information / Other information:
Fire modes: semi, auto
Hop-Up: Yes, regulated
Trigger lock: Yes
Guarantee 12 months

Set includes:
BI-3981M
battery 8,4V 1100 mAh
battery charger 220-230V
metal HI CAP magazine
sling
tactical handle

Technical details: Name: BI-3981M

Manufacturer: BOYI/DBOYS

Velocity [FPS]: 350

Propultion: Electric propulsion

Gearbox version: Gearbox v2

Type of fire: Single, auto

Made of: ABS + metal

Lenght [mm]: 715 / 795

Innerbarrel length [mm]: 363

Weight [g]: 3500

Battery [V]: 8,4

Battery capacity [mAh]: 1100

Type of battery: Ni-Mh

Magazine type: Hi-Cap magazine

Magazine capacity [pcs]: 300

Hop-Up: Yes, regulated

Blow Back: No