Suggestion boxes (or ballot boxes) are available in a range of materials and versions for use either on a shop floor for collecting competition entries or customer feedback forms, or in an office workplace for employee suggestions. A Lockable version helps you keep things secure.
If you’re looking for something that looks good but doesn’t show what’s inside and is highly cost-effective, then a cardboard suggestion box (or ballot box) could be just what you need. Alternatively, a white acrylic suggestion box is also an option. Essential Sales Products has freestanding or wall mounted versions and you can even have a suggestion box with an integrated leaflet/message holder on the side. Particularly useful for holding the slip you would like people to complete for you.