The 22"x18" bass drum has 16, not 20, lugs. Don't feel short-changed though, 16 is enough and if anything opens up the sound a little. The Tama Powercraft heads, front and back, have Powerstroke-3 ...

As noted by TAMA ... bass drums, one 10”x8” tom tom, one 12″x10″ tom tom, one 16″x14″ floor tom, and one 16″x16″ floor tom, with all drums fitted with the exact REMO heads Ulrich ...