This is a close up of the bit my dad broke ><
The yellow/freen gunk is milliput I put on in an attempt to repair it, which worked for me (using a normal amount of force) until my dad used it, at which point it just cracked AGAIN.
AFAIK its one of GAMES own brand things, was only cheap.
Basically the bit in the middle is the top bit of the trigger part on the attachment. When you squeeze the trigger (underneath) this moves back and pushes the B button (in case anyone couldnt figure it out).
The big "fin" down the middle pushes the button (I think) the small side ones act as a cut-off by preventing the user from squeezing too hard and breaking the controller. What has happened is basically along the base of that fin AND the side ones its cracked fairly flushly as a result of my dad squeezing it hard enough that theyve sheared as a result of hitting the base of the unit meant to prevent the controller from getting damaged by idiots like him. Basically it means that when you press the trigger, the crack widens so that the fin which should press the B button doesnt quite make it ><
Am guessing we should be fairly safe with one which uses a stronger mechanism than shown above, at the risk of the actual controller getting trashed.