difference(){  
cylinder(5,2,2,$fn=200);
translate([0,0,0.5]){
cylinder(5,1.7,1.7,$fn=200);}

}
rotate([90,-90,0]){
translate([-2.5,-1.9,-0.2]){
difference(){
translate([5,0,0]){
cylinder(0.5,2,2,$fn=200);}
translate([5,0.4,-0.01]){
cylinder(0.7,2,2,$fn=200);}
}}}