barbell lock

The most common sizes are 1-inch (standard) and 2-inch (50 mm) Olympic. Spin-lock-style collars are typically made for 1" bars, while most Olympic-style collars are sized for 2"/50 mm bars. Availability ranges from individual 1" spin-lock designs up to collars built specifically for 2"/50 mm Olympic bars.

Common styles include: spin-lock collars that thread onto 1" bars; clamp or clip collars with levers or snap latches for quick release on Olympic bars; and various lock-and-release clip designs that allow fast changes between sets.

Protective features include soft elastomer or rubber pads and protective frames or linings that cushion contact with the bar and plates to reduce scratches and wear.

Some collars are sold individually (common for 1" spin-lock designs), while many Olympic-style collars are sold as sets of two or explicitly as pairs.

Many collars are designed for fast on/off use. Features such as larger levers, unibody designs, snap latches, and quick lock-release clips allow rapid installation and removal between sets.

Some collars are described as compatible with straight bars, EZ curl bars, and super curl bars; other designs target standard 1" spin-lock barbells. Compatibility depends on collar size and style.