$ 4.73



Kits, Individuals, Lubes
Buna-N (Nitrile) Viton, Silicone ,Teflon

For sale are (4) Buna O-Rings for Benjamin Marauder - Bstaley O-Ring Tune

By completing this tune, you will have a better and more consistent shot string.
This has been shown to greatly improve your over-all accuracy rate.

You will receive a set of 4 O-Rings to complete this tune.


4 O-Rings and free shipping! One more than other auctions here!


So What is the Bstaley Tune and O-Ring Mod?


It is DIY. It takes three o-rings, put in between hammer and valve. For a given amount of hammer energy required to open the valve at high pressure, it will open further and

longer at lower pressure. The staley mod clips the top off that peak, and conserves air so the flatter string can continue. It isn't in action for first third to quarter of the string. For

a 25 cal, tuning for ~850 FPS, put the hammer travel at ~4 turns CW from max-CCW. For a 22 cal, it is around 3.5 CW from max. Then adjust preload to deliver FPS at the top

of the fill. If it is too fast at lower pressure, turn travel screw CCW a wee bit. If is on the money at low pressure, and slow at high pressure, increase preload.

Here is Bstaley's link to the O Ring Mod  Click     HERE


Here is another video on how to complete the mod  Click  HERE


Shipping via USPS First Class is included in the price.

I use 1st class mail. Tracking IS NOT provided with 1st class. 

TRACKING is only provided on UPS, Express Mail and Priority Mail shipments.

If your item shows shipped - I don't know when it will arrives.  You can find all your shipping info on your 'My Ebay' page or on the auction page.

 All sets will be shipped the next business day after payment.


Need A Kit Not Listed? Just ask via email me at professorfoam (at) gmail com. 

We can duplicate just about any kit.
Send us a sample kit, we'll make it, then we'll return your kit and some FREE kits for your trouble.

5 Star Satisfaction

Please take a few minutes to review the item you have purchased once you receive it, and then logon to your account to leave us a 5 star rating. Anything less than 5 stars we consider a failure on our end, so if you are not completely satisfied with this item after receiving it, please contact us and tell us why BEFORE you leave us feedback so we can make it right.

Buy with confidence, we take customer service seriously, and we always take care of our customers!



We DO ship internationally, even to Canada!  We ship internationally because we can communicate, and we are able to meet the needs of non-english speaking individuals.  We pride ourselves on good customer service, and it is possible for us to meet the level of customer service we pride ourselves on when dealing with international customers.

Thank you for looking at our eBay items, we hope to have the opportunity to prove to you why we have earned our great feedback through same day shipping to support after the sale. Have a great day!


Attention all Florida Customers!!!

USPS has long delays on First Class Letter shipments. They have been taking 14 days or longer for delivery to the Central and Southern parts of the state, If you want to receive your item faster please upgrade the shipping to First Class Parcel or Priority mail, then you will have a tracking number and much faster delivery time.
Thank you.

On Dec-22-13 at 17:10:01 PST, seller added the following information:

Every buyer gets a MyStoreRewards invitation for cash back