Outer diameter:
      2.3-2.3, 2-2.3, 2-2 OD 8mm, length 18mm, side fixing holes for M3.
      2.3-3, 3-3, 3-3.17, 3.17-3.17 OD 9mm, length 23mm, side fixing holes for M3.
      3.175-4, 4-3, 4-4 , 4-2.3 O.D. 9mm, length 23mm, side fixing hole for M3.
      5-4, 3-5,5-5 , 4-6, 5-6, 6-6 OD 11mm, length 23mm, side fixing hole is M4.
      5-8, 6-8, 8-8 OD 14mm, length 35mm, side fixing holes for M4. (The model has a card spring design fixed, so there is a little tight, is normal!)
      8-10, 10-10 OD 16mm, length 35mm, side fixing holes for M4.
 
Product use scope: metal universal joints suitable for motor straight shaft use, suitable for model cars, model boats, robots and other types of metal adapter use!