Its features include a large claw crane, working vending machine, exploding rock face, a cage (with an exploding wall), a magma dozer, and a water blaster. The set also includes a Duke and Doc minifigure with silver suits, and a Firax and Eruptorr lava monster. The included Power Miner vehicle is no. 16  One obvious element that was already present in the Rock Raiders theme was the occurrence of Rock Monsters and Energy Crystals in the story. However, in the Lego Power Miners, the Rock/Lava Monsters play a bigger role and are included in every set and each Rock/Lava Monster are all named characters with different personalities and traits. The Lego Power Miners and Lego Rock Raiders theme both have settings that take place underground and both themes have each team search for crystals, whilst trying to prevent the Rock/Lava Monsters from eating them. However the difference is while the crystals in Lego Rock Raiders were Energy Crystals with massive power in them, the Lego Power Miners crystals seem to be kinetic energy based instead. While Lego Power Miners collect their crystals for research purposes, the Rock Raiders collect them as fuel for their ship. Another difference between the themes is that the Crystals eaten by Rock Monsters in Power Miners make them release the kinetic energy, causing massive rumbles when underneath the surface. The Power Miners are dressed in blue/gray clothing and their vehicles are green/orange and very large, similar to real-world mining equipment – a difference between this theme and Rock Raiders, which is more futuristic with more compact vehicles and grungier colors. Power Miners also implemented several features that only appeared in the planning stage of Rock Raiders, such as the concept of a mobile base and a common uniform for the miner minifigures. The rock monsters have a flip top head, revealing the crystal stored inside. Keyring variants of rock monsters sent with monthly Lego magazine subscriptions have a fixed metal screw eye through the top of the head, and do not open. The screw eye can not be removed. It rotates, but does not withdraw from the plastic. Although there is a method of removing the metal screw. Large monsters, such as Geolix, have a lever on their back that, when pressed/pushed, swings the left arm of the monster, which allows it to throw either rocks, crystals, or smaller monsters. Geolix and Tremorox (but not Eruptorr) all have studs on their backs for holding onto crystals. Unlike their smaller cousins, Large Rock Monsters cannot open their mouths.