The requirements for the use of derricks during drilling are the difference between mobile phones and mobile phone holders. The derrick is a device used to place cranes, suspend traveling blocks, hooks, lifting rings, elevators and other equipment during drilling or workover, as well as to hoist and store drill pipes, tubing and sucker rods. Requirements for the derrick It should have sufficient strength, stiffness and overall stability, and the mobile phone's requirements for the mobile phone holder. The holder must be able to withstand the weight of the mobile phone.