Dispensing equipment is the delivery mechanism used to apply lubricants or adhesive solutions of varying levels of viscosity in a precise and controlled manner. For medium to highly viscous solutions, the manually operated dispensing gun is a basic unit that relies on the operator for the accurate and consistent application of the fluid. For repeated applications at a fixed workstation, the time pressure syringe system is a popular choice as it uses a proven and reliable application method. The air pressure can be adjusted for materials such as soldering paste, and once the dispensing time sequence is set and the cycle is activated by the foot or finger switch, a consistent and regular dose of the material is pumped through the dispensing needle. These designs also maintain a vacuum during operation so they will prevent fluids with low viscosity from dripping, in between the delivery sequences. The gauge of the needles is selected based on the viscosity and quantity of the fluid, and where plastic, conical dispensing needles are not suitable, metal precision needles offer greater accuracy, while flexible needles are used for reaching around obstructions. Manufacturers such as Metcal, which produce work bench dispensing and soldering equipment, also include accessories such as replacement cartridges and dispensing brushes in their product range.