Zero-phase (linear-phase FIR) filtering, applied to the view and — optionally — to exported data. Notch uses a zero-phase IIR. Filters apply to all channels except those you exclude below.

Transition width: auto (¼ of cutoff). Exclude channels from filtering:

Detect QRS complexes (Pan–Tompkins) and delineate the P, Q, R, S and T components as annotations. R is the most reliable; P and T are best-effort and shown faded. Review and remove any below — they are written when you Save.