This lock surrounds your coupler keeping it safe from burglary. Well show you the operation of this lock, its pretty simple with a unique key. You just turn the key the button comes out and you push the key a little bit and the key comes out. You slide it over your coupler and the pin here comes up so when it goes into the coupler it cant come back out. Thats essentially how it works, now well show you that installed on a coupler. You see here that we have a common coupler trigger latch style. This lock works equally good on this one and other different styles. It simply slides on like so. After its on you push the button in and your set and cant pull this back off. Now well show you how this works with a common A-frame style coupler. You can have the latch down or up, again just slide the lock over your coupler and push the button in and it cant come off. That covers it for part # 63228 trailer lock.