Used Roland KD-8 bass drum trigger pad. Some wear on the head surface, but still works perfectly. I tried to get a good pic of the wear. Also has both of the drum key leg lock bolts, some pics only show one in the holders. See the last pic with both present. Works great with single and double pedals. 

The new KD-8 Kick Trigger Pad’s vertical design not only gives drummers a better feel compared to reverse-type kick triggers, but it also reduces trembling so you get nothing but solid kick sounds. And here’s more good news… the KD-8 can even accommodate double bass!