Wera products include screwdrivers, screwdriver bits, ratchets and sockets, nut-spinners and L-keys. In 2013, the line was expanded to include mechanics' tools (wrenches, ratchets, and sockets). These include&colon; compressors, brad nailers, air ratchets, die grinders, paint sprayers, etc. There are many designs, including levers, screws, and ratchets. Hydraulic motor ratchets with their characteristic higher torque are rare outside heavy industry. Toward the upper end of each shaft are two ratchets. It ratchets up a notch when Guy leaves Bruno's compartment and "forgets" his cigarette lighter. Separate ratchets allow either one or both wheels to be driven. Ratchets are widely used in machinery and tools. Later manual-start clocks had ratchets or other linkages which prevented backwards starting. The mounted ratchets allow for greater control of the duration and timing of the sound. "Kulindroplax" seems adapted to moving through a substrate, with the spicules acting as "sediment ratchets". An example of artificial ratchets is the work by Serreli et al.