These Double ended dildo sex toys come in mostly glass, and silicone. We stay away from those made of vinyl. Some Double Ended Dildos can be manipulated to curve to the user's specifications such as Dilio, or are already formed for dual penetration with or without the harness. Tantus makes the Feeldo line and has recently aded a new line called Renaldo for those who prefer the more realistic cock look. Fun Factory also makes a line called Share with different sizes both non vibrating and vibrating. Both companies have a pocket to insert a vibrating bullet. Fun Factory's bullet is rechargeable though.
For glass Double Ended Dildos, Icicles, makes a wide selection and the Spartacus' Double Ended Dong is very popular due to the ridges at the end. Cool or Chill for erotic sensation play.