r₂ = 15 to 60 mm

h₂ = r₂ = 10 to 30 mm

h₁ (depending on s) = 20 to 25 mm

Volume of the head (without shelf height h₁); V ≈ 0.7854 * dₐ * r₂ (dₐ - 0.86 r₂)