Based on your request, "post: P1_P30.z01" most likely refers to the .
P30 - Post Base Double Channel - Square - Phoenix Support Systems P1_P30.z01
Generally 1-5/8" wide by 1/4" thick, with 13/16" (20.6mm) holes. Based on your request, "post: P1_P30
This is a structural component commonly used with strut systems. Type: Double Channel Post Base. Shape: Square. Holes: 4-hole configuration, 3-1/2". Dimensions: 1-5/8" (41.3mm) wide x 1/4" (6.3mm) thick. Based on your request