Hi guys, anyone know how the adapters work...I was under the impression that when I bought my 901 PT..I could then just buy different adapters to use on it...However, I just noticed that the 401/510 PT's are being sold ( yay!)..But, no 401/510 adapters ( to use on my previously bought 901 PT)...I just placed an order and would like to add to it before it ships but, I am confused....Can anyone fill me in?....Thanks, much appreciated....Ivy