3.5MM audio cable fits bumper iPhone 4

Hey,
Was wondering if anyone knew of any 3.5MM audio cables that will fit in the headphone jack hole in the iPhone 4 bumper? I have a i800 cable from Monster that I bought late last year and while it does fit, you have to force it in (meaning it squishes some of the rubber around the hole on the bumper)...I really dont like the idea because Im sure its going to damage the rubber at some point so I havent done it since trying it out the first time.
Thanks
HP DV7T-Quad Windows 7 iPhone 4 32GB