The spot markers are included in a plastic disk, diameter 25,4 mm, thickness 6,35 mm. The source is in the center of the disk and has a 1,8 mm diameter. 

Following sources can be supplied:
 

• Co-57:      0,925 / 1,85 / 3,7 / 37 / 74 MBq  
• Cs-137:    0,185 / 0,37 MBq  
• Ge-68:      3,7 / 18,5 MBq
• Na-22:      3,7 / 18,5 MBq