I bought one of these to mount my Porta 2 on a Manfrotto 055 photo tripod. Very nicely made indeed and worth the money.

However, be aware that you may need to drill out and tap the centre hole to a 3/8"-16 thread if you want to mount it directly to your tripod legs. As far as I can tell, most decent tripod legs use a 3/8"-16 connection for the head base attachment! I wonder why Vixen do not account for this?!