Each time bullets hit, there a loud, thumping sound, which follows with a loud, ?squish?, when a kill is achieved. I have issues with the headphones that are required to be in my ear cabal. It is water resistant, the battery lasts forever! And it definitely took longer than 30 minutes which is what the instruction diagram suggests. ) There have been countless times since that I crawled to my bedroom at the end of the day because my feet hurt so bad. A big thank you to the company for bringing these back into my life! (Same with my 3 sons teva flip-flops). Zappos for 279. It doesn?t require a new connection. The sensor on the 4a does not seem to be accurate.