These sheaves were used as boom end sheaves as well. Below is a Inventory of the usage:
• (4) per Catalina 320 masthead for non furling rigs
• (4) per Catalina 320 masthead for in mast furling rigs
• (4) per Catalina 320 boom for in mast furling rigs
• (8) per Catalina 320 boom for non furling rigs
• (4) per Catalina 34 and Catalina 36 boom for in mast furling rigs
• (4) per Catalina 350 boom for in mast furling rigs
• (8) per Catalina 350 boom for non furling rigs

• Outside diameter: 50mm (~2")
• Inside diameter: 10mm (~3/8")
• Width: 14mm (~9/16")
• Line diameter: 3/8"

Since these spars are French, all of their products are metric. The fractional dimensions provided are the nearest equivalents.