Flipout--usually the peep has a post where the tubing goes over. The other end is tied to your cable. As for finding the best position, draw your bow (but don't dry fire) and see how the tubing runs-off from the peep to the cable. You would want the tubing maintaining the angle of the post on the peep thru to the cable.
In otherwords, lets say at full draw, your tubing is too low or too high on the cable, you will notice a slight elbow where the tubing comes off of the peep--try and get it straight by moving the tubing up or down on the cable--as that elbow stresses the tubing and would eventually break.
The tubing will break sooner or later over time, but it's best for the tubing to maintain the angle of the post thru to the cable.
Mine came with a little cable clip-like thing that went over the cable. It had the same 'Male' end like the peep did.
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The prey must have the predator, just as the predator needs the prey. One without the other is something less. The wolf without the deer becomes a dog. The deer without the wolf becomes a cow. And what does man become?
Some say parallel to the arrow some say on a plane with the peeps reciever knobby thingie. I say make sure you have as little stretch as possible. You only have to have the peep aligned to your pin(s). It really does cut down on the breakage and reduces your worry.