B series door closer have three power level: B2、B3、B4 Each power level have optional (w) and (d) in same dimension Dual valve, closing and latching speed controlled by two separate regulating valves. The model with (d) can keep opening while exceed 90° Universal application, designed for all standard installation, the angle of slam the door is different: Least is 115° while most is 180° Various colors, such as silver gray, golden and bronze-colored. (Customized available)