There is no one correct answer for how much tugging force to use. The proper amount depends on skin thickness, skin-tube girth, and the amount of slack skin available to be gripped (a broader gripped region spreads out the force so there is less pressure). And the longer the device is to be worn and the further from ready privacy you’ll be, the lower the tugging force should be.
The 4-hour rule is a plan for determining the best tugging force to use with any restoration method. It depends on you being able to reproduce your application and tension setting every time you wear a device. For this reason, “external” sources of tension (straps, weights, extender rig) are preferred for beginners. Self-tensioning methods like Packers require the user to create skin tension with the hands while the retaining cone is being secured, so these are less reproducible and more challenging for implementing the 4-Hour Rule. Likewise the TLC-X springs give the advantage of a compact profile, but the tension is not precisely reproducible.
We recommend tugging for 8 – 12 hours per day. That time will be broken up by necessary trips to the toilet and by other interruptions. You should wear your skin retained over the glans all non-tugging hours with the Your-Skin Cone.
You need to use a tension setting that will stay comfortable from the time you apply the device until the next interruption. This might typically be 4 hours (for example, the time between breakfast and lunch).
So to use the 4-hour rule, apply your tugging device to your penis. Add zero tension (no tension at all). Then wear the device for your desired duration (perhaps 4 hours). If you can do this several times across a few days with no pain or unwanted effects, then you might increase your tugging force (or pusher extension) by a tiny increment.
Continue increasing every few days until you have unavoidable discomfort within your desired wear interval. When you find that 4-hour comfort is impossible then revert to the previous tension setting. (“Occasional” discomfort can occur even with a perfect tension setting. Never tolerate pain; re-apply or remove the tension immediately).
This method gives you the proper setting for tugging force. Wearing gentle tension will with time give you increased slack skin. Even though the tension will be so gentle you could forget you’re wearing it, you will know it is working effectively because you will measure your Forced Erect Coverage (FEC) monthly.
Always apply a freshly washed device to freshly washed skin.
Even if you do everything perfectly, your device will sometimes get out of adjustment and start to cause pain, sometimes described as a mild pinching or burning sensation. If the local pressure on the skin exceeds your systolic blood pressure then blood flow will be promptly impeded. That’s when the discomfort of ischemia occurs.
If this happens only occasionally, you can just re-apply the device and try again. If it happens within 4 hours every time you wear the device, then you need to reduce the tugging force or perhaps investigate if your device is the correct size for you. The more skin you grip within the retainer the lower the stress (Stress is Force divided by Area). This also means when you increase the area of gripped skin you can use higher tension.
If you tug in bed this becomes an 8-hour rule. The same steps apply.
Starting with zero tension may seem tedious, but within a week or two you will be dialed in to your ideal tension setting. Proceed with caution. Injuries to the skin have been reported even with no pain warning. One User Forum member reported that some broken blood vessels happened the very first hour he tried a ventless tapeless device. He had no idea anything was wrong until he took the device off to urinate. It cleared up within a week. The ventless devices create a vacuum around the glans, and unfortunately as with all vacuum methods there is a risk of bruising from burst blood vessels. There is no way to know we are approaching the tension level at which this would start to occur for an individual. Proceed with extreme caution when using ventless devices.
To recap, if it often gets uncomfortable before you were otherwise ready to take it off, you’re tugging too hard. If it never gets uncomfortable, maybe you could go stronger. To cycle through testing each tension level for a few 4-hour stints can take weeks. Once you’re dialed in, that’s it – that’s your setting until something else changes. This isn’t like body building where you hope to keep building up to higher resistance.
And note that for some guys starting out tight, just applying a device – with no added tension – may indeed give plenty of tension.