This product is a 180 KHz fixed frequency PWM buck (step-down) DC/DC module,capable of driving a 5A load with high efficiency, 
low ripple and excellent line and load regulation. 
The DC/DC buck module has applications where the input voltage is higher than the output voltage , such as battery, power transformer, DIY adjustable regulated power supply, LCD Monitor and LCD TV portable instrument power supplytelecom/networking equipment,24V vehicle notebook power supply,industrial equipment buck. 12V buck to 3.3V, 12V buck to 5V, 24V buck to 5V,24V buck to 12V, 36V buck to 24V etc.

Specifications:

• Input voltage range438VDC(Note:input voltage not exceeding 38V)
• Output voltage range1.25-36VDC adjustable
• Output current: 0-5A
• Output power: 75W
• High efficiency up to 96%
• Built in thermal shutdown function
• Built in current limit function
• Built in output short protection function
• Input reverse polarity protection: None (if required,you can attach high current diode in series with the input).
• L x W x H = 5.4*2.3*1.5 CM