more costly examples use a larger commercial motor and a belt, with no gear reduction to spin the burrs. The latter example is termed "direct drive". The reduction gear versions are noisier and usually do not have the lifespan of the direct drive units. Electrical powered burr grinders are available in many variations. Some grinders are "stepped" meaning that they are fixed by the factory into a set series of adjustments while "stepless" varieties use a worm drive or other mechanisms to offer a near-infinite number of adjustments within their grind range. Other variations include grinders that are equipped with dosers and others that are "doserless". Dosers function as a catch bin to collect the ground coffee and by using a lever, users are able to dose a set amount of coffee. Doserless versions remove the bin and dosing function, and the grinder outputs the ground coffee directly into an espresso machine portafilter or into another container. The doserless examples normally feature additional functions such as weight based or advance time based grinding in order for a barista to grind for an exact amount of grounds required for a specific espresso shot. Manual coffee grinders have been largely supplanted by electrically powered ones for speed. Manual grinders are used for convenience and aesthetic reasons and are usually less costly than electric models. An example is the manual Turkish coffee grinder; these are inexpensive and can grind coffee to fine powder for Turkish coffee. Manual grinders Manual burr grinders are turned by hand, rotating one grinding surface against the other. Coffee mills usually have a handle, providing leverage for the many turns required to grind enough coffee for a cup. The ground coffee is collected in a container which is part of the mill. Salt, pepper, and spice mills, essentially the same as coffee mills, usually do not have a handle, the entire top rotating instead. While this is less convenient, only a few turns are required to grind enough. The ground product falls directly onto the food being seasoned; the mill has no container. A few designs have abrasive surfaces which do not rotate; each squeeze of the handles moves one flat plate past another, then the plates are restored to their original position by a spring. Many hard spices are available in containers incorporating a simple cone burr grinder, intended to be discarded when empty. Most grinders can be