Health crates appear as an iron two by two block with a silver wrench on it. The block is mainly silver coloured, but it also has a red stripe across the middle.
Health crates are usually spawned when the player defeats an enemy tank. When spawned, the drop to the ground with a parachute attached to the top. It will drop all the way to the ground, then just stand there. When it is clicked, all tank blocks, the engine room, man blocks and guns are replenished to full health. Sometimes, the health crate will not drop and the next tank will come out, then probably the health crate will drop.
A health crate will drop even when the player completed the level. To conserve time and repair more blocks at once, the player can attach blocks to their tank then click the health crate, which will health replenish all damaged Blocks. If the player moves away from the health crate, it will begin to flash and eventually disappear if not clicked.