FlubberStufferz 4.75 have evolved! Soft shown in Purple Medium shown on Green Firm shown in OG Purp(pink) We took our original design and made a few enhancements! The outer ring has been smoothed out 50% via cell design, yet still remains non-continuous. We have also dialed in our inner ring and bevels, this helps to hug all clamp rings very tight to secure placement, and make it pain free for mounting on more narrow wheels! All 3 versions, soft, med, firm have received these updates. Soft has received a slight change to the 3rd stage. We have adjusted the angle and rotation to give a tad more 3rd stage support and help our Forward Propulsion Technology give more action under heavy load. Ideal for light to medium weight rigs in fronts, and could be used for rears if your sub 5lbs and looking for the extra conformity instead of support. Medium is a all new version, it incorporates our new No Flat 3rd stage! Ideal for medium to heavy weight rigs for use in fronts, and for light to medium weight rigs for rear tires. Firm is also new and will replace the HD version. This has our No Flat stage for both the 3rd and 2nd stage. It is very supportive due to the dual No Flat stages, yet still allows the tire to do light conforming duties under normal load. Ideal for those looking for the extra support for rear tires on heavy to medium weight rigs. Baseline weights are listed, your choice will depend on the rigs weight, your desired conforming rate, and the tire itself can have an impact on support. 🟢 Soft (sub 6lbs) this is our original/standard insert, it is very soft and is reccomended for light weight comp rigs for use in fronts. This does not have our "No Flat" 3rd stage, this keeps things extra soft for those looking for ultimate conformity yet stout side wall properties. Comes standard with our Directional Conforming Rates, and Forward Propulsion Technologys. 🟢 Med (sub 9lbs) this is our mid range insert that comes standard with our "No Flat" 3rd stage. This provides support for either front or rear and keeps the tire from appearing flat yet still allows for conformity in the 1st and 2nd stages. The no flat stage will indeed conform under heavy load when required to. Also comes standard with our Directional Conforming Rate, and Forward Propulsion Technology. 🟢 Firm (10 lbs). This is our new Heavy Duty Insert, and replaces the old HD insert. They are made from our standard material, which gives a plush first stage to allow conforming to happen, yet utilizes dual No Flat stages to give plenty of support for heavy rigs and absolutely the best side hill action in the Insert Industry. Most will find the medium insert to be sufficient for support. But if there is any doubt, the new Firm is here to ease those concerns! Package contains 2 insertz. (Insertz are printed in our brand colors. They will come in one of 2 colors, random selection, green or purple) We recommend venting your tires when running our Performance Inserts. They are waterproof, temperature and mildew resistant, and designed to support without the need for sealed setups. ***All products are made to order. Please check the header on the main page for approximate lead times. Thank you for your support and patience - FlubRC