The Brother Waste Ink Box LEB445001 is a maintenance component for collecting excess ink produced during printer operations. It helps keep that waste contained as the printer runs its routine processes.
The listing gives an approximate yield of 600,000 pages and identifies the Brother HL-S7000DN, HL-S7000DN50, HL-S7000DN70 and HL-S7000DN100 as compatible models. This gives you the part reference and supported printer models for maintenance planning.