Next up and new at the zoo is a kit of parts to make a Pull Pin style switch, excellent for remove before flight arming or there are options and features that make this attractive for low friction " Drop a payload with the pin staying on the vehicle" type systems!
Finally completing the trio of bits is a little assembled PCB which acts as a polarity protector, these are small enough to be soldered inline in a cable and covered with a little heatshrink, they can work at any voltage up to 20V DC and with a max current of 4.3A. If ever the power is connected backwards no current can flow through the board and both the board and the attached project will be undamaged. Connected correctly the little board draws less than a milliamp with no step down in voltage. Neat and can save your expensive experiment/avionics/altimeter etc on the other side! Check out the whole store here.