3-3/4" handle spacing, 4" bellcrank with 11/16" throw to upper Flap horn 1-1/4". Lower flap horn elevator push rod 3/4", elevator horn 11/16". This is the smaller Tom Morris system that works well up to 600 Sq. In. planes.The legs that go into the flippers should be 1" to 1-1/2" depending if they're into hard wood or glued in balsa.Motorman