These include e.g. vine trimmers (for grapevine), and tree trimmer (tree toppers). It has also been used in outboard motors, string trimmers and lawn mowers. These very large trimmers are often referred to as brush cutters. Nylon filaments are primarily used in brushes especially toothbrushes and string trimmers. There are three surgical methods&colon; scalpel blade, guillotine trimmers, and laser. Their cutting mechanisms can be very different from hedge trimmers. Several companies manufacture beard trimmers designed to maintain the designer stubble look. Different designs as well as manual and powered versions of hedge trimmers exist. Propane-powered string trimmers were also manufactured by Lehr. There are electric string trimmers that offer the same performance as gasoline-powered trimmers. Other companies, such as John Deere, now carry low-emission two-stroke engine trimmers. Most trimmers use two stroke engines and require gasoline mixed with oil. Clarkson was seen with a pair of open hedge trimmers, which he then snaps shut. Its wick trimmers and trays are to be of pure gold. Capacitor trimmers can be also used for frequency adjustment of the oscillator circuit.