[Set] WE13 13" M4/AR-15 Knight's Armament Airsoft Rifle, 30 RPS, ETU - Tan [WELL PRO] + STANAG M4/AR Mid-cap Magazine 90 BBs [WELL PRO]

Replica category referring to general platform types, e.g. AK, AR15.

Type of magazine included with the replica (e.g. hi-cap, mid-cap, low-cap, gas), defining its design and capacity.

Fire modes available in the replica (e.g. semi-auto, full-auto, burst), affecting the firing style.

Battery connector type (e.g. Tamiya, T-Deans), important when choosing a battery and charger.

Type of internal replica mechanism (e.g. V2, V3), defining the standard and parts compatibility.

Type and diameter of bearings used (ball bearings or bushings), affecting gearbox operation, e.g. 8 mm bushings.

Blowback effect simulating bolt recoil, increasing shooting realism.

BB hop-up system improving range and accuracy by applying backspin, extending the flat trajectory.

Thread direction of muzzle devices at the end of the barrel, allowing the selection of accessories such as a suppressor or tracer unit.

Recommended BB weight for use with the replica.

Individual designation identifying a specific replica unit.

Number of BBs the magazine can hold.

BB muzzle energy expressed in joules, measured using 0.20 g BBs, defining the actual force delivered.

BB velocity after leaving the barrel, expressed in feet per second (FPS), measured using 0.20 g BBs and without hop-up applied.

Electronic unit improving gearbox operation by controlling the gear cycle and enhancing trigger response. Some ETUs allow programmable settings to customize replica performance.

Material the replica body is made of – most commonly aluminum alloys or polymer (plastic).

Type of magazine included with the replica (e.g. hi-cap, mid-cap, low-cap, gas), defining its design and capacity.

Number of BBs the magazine can hold.