Some types of recommended equipment are below. Click the picture or the link to purchase online.
Use the spike end to unjam your ropes or to poke at your partner in sexy fashion
One of my favorites for separating my ropes for complicated up lines and suspension work. Use with Carabiner's
Great for separating up lines for complicated suspensions
Use the seatbelt cutter (not the knife). Works on up to 1/2" rope and also small enough it that fingers and toes don't end up inside of it.
Because sometimes you want them to spin and not twist up your lines.
Overall a good wide gate opening and since they are oval and don't have a point less prone to jam your up lines together.
Weight rated, light weight and fits over most any tree limb or ceiling truss. You'll start seeing hard points everywhere.
Sometimes bigger is better. Avoids the risk of sliding mobile rigs and 4x4's are easily replaced if they get worn with a simple trip to home depot.