Pan cake slip rings are used when length is at a premium but diameter is less restrictive. Any dimension of through bore or solid is option.

Slip rings also called rotary electrical interfaces, rotating electrical connectors, collectors, swivels or electrical rotary joints, are commonly found in electrical generators for AC systems and alternators and in packaging machinery, cable reels, wind turbines. High speed data transmission slip ring and high frequency slip rings which market starve for are popular now.