Strong weight capacity, metal shaft block system Specification:Diameter: Φ28, 36, 38.Standard weight capacity: 5.0KgMaximum weight capacity: 10.0KgAssembled ball chain: L00-10#P6.2We have six models under this heavy roller blind series as following: L140-28A, L140-28B, L140-36A, L140-36B, L140-38A, L140-38B. Please send inquiry to us if you are interested.