Capacities range from single-person containers up to multi-quart buffet pans — common sizes cited include about 6 QT for roll-top chafers, 9 QT for some electric chafers, and 12 QT for larger commercial warmers; hotel pans also appear in GN 1/6 depth (≈4 inches).
They’re heated either by fuel-based chafing setups (sternite/fuel cans under the water pan) or by electric systems with built-in heating plates or hot-water elements — for example, some electric units use a 600W heating plate.
Power outputs vary by size: small personal warmers around 50 W, many electric chafers about 600 W (built-in plate), and larger electric trays or steam-table units up to roughly 1,500 W.
Stainless steel is the most common material; other items mention glass and PC (polycarbonate) components, with various metal or plastic parts on smaller portable units.