Will this cover my problem for not enough 3 pin fan connectors, and I have 2 fans at this moment I want 3 more put in my case back side and front all 120m and 1 140m I have 1 connected to the mother board and one already connected to the psu Not sure how many Molex I have left over
this is my current psu http://www.newegg.com/Product/Product.aspx?Item=N82E168...
In regards to the Rosewill splitter you linked. Yes, you could use that to add more fans.
Although you can use 3 pin fans with the splitter it's geared towards using with PWM fans (4 pin connectors) though so keep that in mind. The purpose of that splitter is to connect the one 4 pin connector to your CPU cooler's fan, then the other two connectors (PWM connectors but 3 pin) to two PWM fans. What this results in is all the fans being controlled by PWM. So the speeds will varie depending on the CPU tempature.
The reason the two connectors have 3 pins instead of 4 pins even though they are for PWM fans is so the RPM readout isn't sent to the motherboard. It allows only the CPU fan RPM readout to be sent so that it is not receiving 3 RPM signals and confusing the board.
Now....if all you want to do is simply add some full speed 3 pin fans you can simply just daisy chain them to one molex connection (Assuming you have 3 pin to molex adapter), or connector to your motherboard, or buy a 3 pin splitter instead, or buy a fan controller. Lots of options.