Other examples of NFV include virtualized load balancers, firewalls, intrusion detection devices and WAN accelerators. Other mitigating techniques involve setting up reverse proxies, firewalls, load balancers or content switches. Wheel Balancers and tire changers are produced in Conway, Arkansas. Testing firewalls and load balancers involves expenditure on hardware, software and its maintenance. Examples of positioning equipment include lift/tilt/turn tables, hoists, balancers, manipulators, and industrial robots. All 425 engines were fitted with forged steel crankshafts with harmonic balancers. In tire manufacturing factories, static balancers use sensors mounted to the spindle assembly. F5 Networks load balancers support one-armed and multi-armed configurations. Blade balancers are used on parts such as fans, propellers, and turbines. Load balancers distribute the work over the set of virtual machines. Hardware and software load balancers may have a variety of special features. The engine featured counter rotating balancers, which reduced vibration and allowed a lighter frame. Other balancers and leapers include the mountain zebra, mountain tapir, and hyraxes. In early 2017, DigitalOcean expanded their feature set by adding load balancers to their offering. Balancers are often found in lithium-ion battery packs for laptop computers, electrical vehicles.