41677 - Technic, Liftarm Thin 1 x 2 - Axle Holes. 6632 - Technic, Liftarm Thin 1 x 3 - Axle Holes. 32449 - Technic, Liftarm Thin 1 x 4 - Axle Holes. 2825 - Technic, Liftarm, Modified Stud Connector Thin 1 x 4.
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