Scientists have come up with bizarre new iPhone app that helps men measure their manhood.
The penis testing tool is designed to help fellas find the perfect condom to fit their bits.
Dubbed Condom Size, it turns your iPhone into a ruler that can be used to measure the length and girth of your bits, the Sun reported.
To find out length you simply line your manhood up against the screen.
Girth is a bit more tricky - you're asked to tie a piece string around the widest part of your willy, and then hold that up against the onscreen ruler.
After you've entered your measurements, the app recommends a condom - and tells you how you rank against other manhoods around the world.
Costing just 69 pence, the App's bound to be popular with men desperate to find out how they measure up.