The product is a fully natural rubber based Buffer Spring. THere ar two sizes, one is big and anothner is small.
For big one, there are two major variety of this product, one is 500DN and another is 300DN. 500DDN is intended for 2000 Kg end load and 300DN for 1400 Kg.
For the smaller there are two major variety of this product, one is harder (Type A) and another is softer (Type B). For Type A in 10 mm Deflection the load range required is 990 - 1210 Kg and for Type B in 60 mm Deflection the load range required is 2340 - 2860 Kg
Compressive Deflection Charts
Note: General Tolerance ±15%