Used these for an Einstein Halloween costume last year and, for the most part, they work fine.  The eyebrows are better than the mustache at staying on.  I found underneath the mustache gets wet with sweat and falls off easily.  A little double sided tape HELPS but didn't solve completely.  Spirit gum may be the thing to use to keep it on.  You get what you pay for... this will work and look fine but with a little added effort.