This read-write object specifies the burst size, in bytes, for this metering class's token-bucket algorithm, with zero meaning the device should pick a suitable burst size automatically, and the description notes the resulting time interval can be derived from burst-size times 8 divided by rate. An admin tunes this to control how much traffic can burst above the configured rate before shaping kicks in. For example, an admin wanting to permit brief traffic bursts above the committed rate for a bursty application would raise this burst size rather than leaving it at zero.