The dog carving on the lid is pieced atop.  This is a puzzle lock. The key to opening the box is lifting the dog's ear flap at the edge. That piece is a pin that holds the box shut. Removing that upwards, the lid then slides open, pulling it forward. Inside is another lid that, on its other side, has gift designations carved - To:  From:  Occasion:  Date:  The treasure or trinket compartment is lined in black fabric. At the bottom is marked Carver Dan's Handcrafted Vietnam. The box measures 6-1/2" x 3-1/2" x 1-3/4" high. 

Very good condition. There is a pinprick at the bottom of the lock piece - don't know if that was in the original carving. 

Thanks for looking!