"The AEO Photo Lightning Strike Pro 4.0 Lithium Shutter Trigger is a light-activated camera triggering device to capture images of lightning, fireworks, gunfire and other light-generating events. It improves upon version 3.0 with the inclusion of a new Lithium 14500 rechargeable battery that, along with the unit's lower power consumption, enables up to 180 hours continuous operation on a single charge. The Pro 4.0 model provides built-in battery charging capability via its USB Micro B input which features an internal charge safety circuit. The unit can also be powered by the USB connection while charging or without batteries installed. A low battery LED indicator is providedAlso, a low profile "positive action" switch design prevents accidental activation, optimized noise immunity reduces unwanted firings and a 0.3 ms trigger lag time serves to capture shots that might otherwise be missed. The Pro model features a manual sensitivity control override for exacting control of trigger activation. The Pro Trigger is very compact, measuring just 2.75" long and attaches directly to your camera's hot shoe mount and offers a locking hot shoe and tripod mount. Its 2.5 mm built-in connector accepts cables (sold separately) from numerous cameras. Proprietary electronics allow for image review after every shot and a low profile LED minimizes reflection of light when used shooting through windows and windshields.|Operates on a single Lithium-Ion 14500 (AA) 3.6V rechargeable battery. Low power design enables up to 180 hours of continuous shooting on single charge. The Pro model includes a built-in USB Micro B charging port|Detects lightning in the distance and triggers your camera with only a 0.3 milliseconds lag and 1.5 kV isolation from camera electronics. Manual Sensitivity Control Override allows exacting control of trigger response for unique shots and when workin|Attaches directly to your camera's hot shoe with a locking hot shoe and tripod mount|Proprietary electronics allow for image review after every shot|Low profile "positive action" slide switch will not accidentally activate and drain battery|Low profile LEDs minimizes reflection of light when used shooting through windows|The Lightning Strike! 4.0 version has been upgraded to improve its noise immunity from man-made sources. This helps to reduce unintended camera firings from cell-phones, car lights, etc|Compatible with numerous cameras based on separate purchase of camera-specific cable. 2.5mm interface accepts all AEO cables for a variety of cameras"