trailer manual slack adjuster 1good shell strength 2good modulus of elasicity 3durable 4resonable price Our company has superb technical strength, ... Manual Slack Brake Adjuster1.spline teeth 10(still can produce of 8,10,14,28,37)2.holes 2(still we ... can produce holes of 1,2,3,4)3.net weight:2.3kg4.teeth ...