Report Universal Socket block? Mixing brands for your rig? in Steadi-Newbies Posted April 26 I'm about to get a used rig from a friend, it's a Proline Raven sled and a Proline arm. I'm also getting a vest but was advised to get a new one as this piece was pretty worn. I was thinking of investing in a Tiffen Exo Vest. It's an adjustable one size vest but wanted to know the smallest dimensions it can be. When talking with customer service, they're not sure about mixing Proline with Tiffen. I've heard about the Universal socket block and how you can have one brand of an arm but a different branded vest. I'm not getting any information on whether Proline has this. Anyone have any insight? Thanks guys!