Possible Clues:

• Record portions of some musical compositions?
• They have a reputation for sizing up what's in 20 down for judge in recordings
• They enable one to determine length and width
• They have a reputation for sizing up judge in recordings
• They have a reputation for sizing up amount in wraps
• What musicians used to produce to test first songs from The Carpenters' bits and pieces
• They're for sizing up what the winner is expected to go through to determine final times