I recently had the opportunity to test out Calculated Industries’ new leveling tool, the AirShim. This little inflatable bag is designed to support up to 300 pounds and span gaps from 3/32 inch to 2 1/2 inches. A hand pump fills the bag, and a push-button valve deflates it, allowing the user to regulate the bag’s thickness as needed. An almost identical tool—the WinBag—is offered by Red Horse USA; it’s designed to support up to 220 pounds and span gaps from 3/32 inch to 2 inches.

It’s called a shim, but it functions more like a pry bar. Unlike pry bars, however, this handy tool doesn’t leave a mark on the workpiece, because it’s made of a proprietary synthetic material that stays slightly pliable as it’s inflated. One of the nicest features of the AirShim is that it fits snuggly into a tool pouch and doesn’t add any noticeable weight. When you’re on a ladder, this is particularly helpful.

This article originally appeared in Tools of the Trade.