prawn で定義されている用紙サイズを参照する方法

#!/usr/local/bin/ruby
# -*- coding: utf-8 -*-

require 'prawn'
require 'pp'

Prawn::Document::PageGeometry::SIZES.each do |size|
  pp size
end

出力

["4A0", [4767.87, 6740.79]]
["2A0", [3370.39, 4767.87]]
["A0", [2383.94, 3370.39]]
["A1", [1683.78, 2383.94]]
["A2", [1190.55, 1683.78]]
["A3", [841.89, 1190.55]]
["A4", [595.28, 841.89]]
["A5", [419.53, 595.28]]
["A6", [297.64, 419.53]]
["A7", [209.76, 297.64]]
["A8", [147.4, 209.76]]
["A9", [104.88, 147.4]]
["A10", [73.7, 104.88]]
["B0", [2834.65, 4008.19]]
["B1", [2004.09, 2834.65]]
["B2", [1417.32, 2004.09]]
["B3", [1000.63, 1417.32]]
["B4", [708.66, 1000.63]]
["B5", [498.9, 708.66]]
["B6", [354.33, 498.9]]
["B7", [249.45, 354.33]]
["B8", [175.75, 249.45]]
["B9", [124.72, 175.75]]
["B10", [87.87, 124.72]]
["C0", [2599.37, 3676.54]]
["C1", [1836.85, 2599.37]]
["C2", [1298.27, 1836.85]]
["C3", [918.43, 1298.27]]
["C4", [649.13, 918.43]]
["C5", [459.21, 649.13]]
["C6", [323.15, 459.21]]
["C7", [229.61, 323.15]]
["C8", [161.57, 229.61]]
["C9", [113.39, 161.57]]
["C10", [79.37, 113.39]]
["RA0", [2437.8, 3458.27]]
["RA1", [1729.13, 2437.8]]
["RA2", [1218.9, 1729.13]]
["RA3", [864.57, 1218.9]]
["RA4", [609.45, 864.57]]
["SRA0", [2551.18, 3628.35]]
["SRA1", [1814.17, 2551.18]]
["SRA2", [1275.59, 1814.17]]
["SRA3", [907.09, 1275.59]]
["SRA4", [637.8, 907.09]]
["EXECUTIVE", [521.86, 756.0]]
["FOLIO", [612.0, 936.0]]
["LEGAL", [612.0, 1008.0]]
["LETTER", [612.0, 792.0]]
["TABLOID", [792.0, 1224.0]]