Use toggle latch clamps to keep two halves closed tightly or loosely as you like. Just screw the tension hook to get the maximum tightness.

Features:

Includes: 6 Pack adjustable toggle clamp latches and 24 screws
Easy to install: just fix them with the screws provided
Installation distance is adjustable: maximum overall length is 4 and 1/8 in , lock up range from 3 and 1/2 to 4 and 1/8 inches long
Made with premium metal plating zinc for corrosion resistance and anti-rust. Works well for different temperature environments: indoor or outdoor. 
Soft plastics cover handle for easy, safe and comfortable operation.