All collimators are hex-hole cast lead.
Spatial resolution is slightly degraded as well, the degradation gets worse as you get farther from the face of the collimator. Suitable for renograms, lung perfusion, and pelvic bone scans. Focal point is 20 cm from the center of the collimator face. Spatial linearity is somewhat distorted, the non-linearity gets worse as you get farther from the face of the collimator. Suitable for thyroid and other small-organ imaging.