C Connectors are typically used with Ludlum meters and probes.  These are used C cables.

Add a Counts.Pro for $399 to turn your meter into a digital scaler/ratemeter/cloud connected datalogger that records your entire survey for complete and easy archival and documentation.  Take your meter to the next level with Counts.Pro

Works in your meter and any of the following IOS devices:

iPhone

• iPhone 4s
• iPhone 5
• iPhone 5c
• iPhone 5s
• iPhone 6
• iPhone 6 Plus

iPad

• iPad, 3rd generation
• iPad, 4th generation
• iPad mini
• iPad mini 2
• iPad mini 3
• iPad Air
• iPad Air 2

iPod

The iPod Touch (5th generation) is equipped with Bluetooth 4.0.

The Counts.Pro App is in the apple store here: 

Visit https://itunes.apple.com/us/app/counts-pro/id1281397288?mt=8