Used correctly, this trap is highly effective.  TIP:  Watch every YouTube video you can find regarding its use and take what you can from each of them as they all have various tips and tricks that you'll find helpful.  Keep in mind:  No trap will work every time as you're dealing with an unpredictable living rodent.  The more you use it, the better you will become at its placement and subsequent results.  BEWARE:  This trap is vicious and will break your finger if you give it the opportunity to do so.  I am not exaggerating this point.  There is a 'lock' on the top of it that you flip into place after you set it.  Use that or you may break a finger during placement.  And, DON'T forget to 'unlock' it when you have it in the ground.  It's easy to to do.