Here's a General Description of the Arms:

Material: The replacement arms are constructed from carbon fiber, a material known for its strength and lightweight properties. Carbon fiber is commonly used in quadcopter frames due to its excellent strength-to-weight ratio.

Arm Thickness: The replacement arms are 4mm thick, providing extra durability compared to thinner arms. Thicker arms can withstand more stress and impacts, making them suitable for more aggressive flying styles and racing.

Compatibility: These replacement arms are specifically designed to be compatible with the ZMR250 V2 quadcopter frame. They should have the same hole patterns and dimensions to ensure a proper fit.

Motor Mounting: The arms will have pre-drilled holes or mounts for attaching brushless motors. These motor mounts are typically reinforced to handle the forces generated during high-speed flights.

Mounting Holes: The arms will include pre-drilled mounting holes for attaching the arms to the main frame of the quadcopter. These holes should align with the existing frame components for a secure and proper fit.

Cutouts and Features: The replacement arms may include cutouts or design features aimed at reducing weight without sacrificing structural integrity. These features could include holes for wire routing or other design elements.

Assembly: Installing the replacement arms should be a straightforward process, involving attaching them to the main frame using screws. Ensure that the replacement arms align correctly with the existing frame components.