These relays are operated from an unused channel on your receiver and work great. I have them in a couple of model planes. The larger one, http://www.robotmarketplace.com/prod...-BATTLSW1.html and the smaller one, http://www.robotmarketplace.com/products/0-PICOSW1.html . They are great little relays and are rated for up to a million cycles. You can't go wrong with them and weigh very little.