Specifications:
Output: 5 V/ 3 A or 6 V/ 3 A switchable
Input: 5.5 V-23 V (2-5S LiPo pack, 5-15 cells NiMh/NiCd pack)
Size: 42 x 17 x 7 mm (Length x Width x Height)
Weight: 9 g

For a traditional linear BEC, for example, a 4S lithium battery pack has a typical voltage of 14.8V, in order to let BEC output 5V/ 1A, the current flow into BEC is at least 1A, so the power on BEC is 14.8V x 1A= 14.8W. But the useful output power is only 5V x 1A= 5W, so the efficiency of BEC is just 5W/ 14.8W= 33.8%, the redundant power 14.8W-5W= 9.8W changes to heat, which makes the BEC very hot.
For a switch-mode BEC in the above case, in order to let BEC output 5V/1A, the current flow into BEC is only 0.38A (actual test data), so the power on BEC is 14.8V x 0.38A = 5.6W, and the efficiency of BEC is 5W/ 5.6W= 89.3%.

If the UBEC is supplied with a switch, it allows the power to the RC components (receiver, servos, etc) to be controlled via this switch. Please note that the “ON” & “OFF” state of the switch are logically reversed with the output state of the UBEC. When the switch is “ON” (switch closed), the UBEC output is shutdown, when the switch is “OFF” (switch opened), the UBEC output is normal. This feature allows the switch to be cut off if it is not needed (saving weight) which allows power to RC components to be controlled in the usual way by connecting and disconnecting the main battery pack. (The switch is optional)