Related Clues:

• Colon in an emoticon
• Dimensions and tolerances, say
• Camera parts
• Monocles, basically
• Building plans, for short
• Orbs
• Contractor's info
• Architect's plans, briefly
• Contractor's concern
• Contacts, e.g.
• ''Electric'' sensors
• Tech details
• Optometrists' concerns
• They may be black or blue
• Architects' reading