union() {
	difference() {
		cylinder(h=30, r=25, $fn=300);
		translate([0, 0, -5])
            cylinder(h=40, r=23, $fn=300);
	}
    difference() {
        union() {
            translate([0, 0, 30])
                cylinder(h=3, r=30, $fn=300);
            color("green")
                translate([-22, -12, 31])
                    cube([44, 24, 5]);
        }
        color("red")
            translate([-20, -10, 25])
                cube([40, 20, 15]);
    }
}