The outer shell of the rectangular collimation is made of iron, with a rectangular appearance and square field of view, which makes the rectangular collimation system stable.
In order to ensure that the rectangular beam limiter can emit X-rays properly, the outer wall of the x ray collimator is made of double lead-lined material. The rectangular collimation uses lead leaves to control the size of the field of the X ray, and the leaves also contain lead. Two pairs of lead blades are at the entrance of the ray, two pairs of lead blades are in the middle, two pairs of lead blades are at the exit of the ray, and a rectangular collimation contains six lead blades.
There is a ruler on the right side below the rectangular collimation, which can measure the distance from the rectangular collimation to the bed surface and estimate the SID.