To start the thread off, anyone whom has read my previous meanderings is familiar with my use of MOA sloped or 1 piece picatinny style bases and when compared to other similiar base manufacturer's in the same price range or less, the D.I.P. (Diversified Inovative Products Diversified Innovative Products - Main Page) bases offer alot more for the around the same price as others. So when I received my CZ 455, there was no doubt that the first addition to it was a D.I.P. 25 MOA base. D.I.P. makes an extended length and shorter version for the CZ, in 25 MOA, flat, and in left handed versions - all in 3/8 or 11MM dovetail applications. At the time of this review price ranges from $42.97 to $46.97, which seems more than resonable as these are do it yourself installs - no need to pay a gunsmith. There is even a model or two for the centerfire CZ 527. First about D.I.P., they are doing things right....in a world where customer service is practically non-existant, D.I.P. gives next or same day processing of an order, and I had received my items in 3 days, even using standard postal delivery. Any questions you may have are actually answered personally from the owner of the company honestly and in a very timely manner - adding further confidence to your purchase. Instead of selling you a bill of goods you don't need just to make a sale and leave you "hanging", they actually take care of their customers, provide handy quality products (some exclusive to D.I.P.) for rimfire / centerfire rifles and a few pistol items at a price that doesn't let you feel taken advantage of. New usefull products are developed and added every few months. ***This is not a paid endorsement or am I affiliated in any other way with D.I.P., just an "Atta boy" to a company that does good business - rarely found these days, and Made in the USA is the icing on the cake.*** Some of the advantages of a MOA sloped base or even a flat picatinny base: 1. It "tilts" your scope forward, allowing for more adjustment to be made on your optic for longer shots. 2. Allows more options to mount your optic in regard to eye relief, ring placement, and scope clearances both with the bolt handle and with the objective lens (the bases have a higher profile). 3. Tends to stiffen the receiver, even if just slightly. 4. In the case of the CZ, allows any Weaver or Picatinny style rings to be used. 5. Allows the attachment of rail mounted levels / other accessories if desired. So back to the base in question - the CZ 25 MOA 1 piece scope base. The finely finished base came with six 1/16th (at least that's what size I used) hex set screws. The bottom of the base has an 11MM (at least in my case) groove that simply slips over the 11MM receiver. It works as a tongue and groove application. 1. As when handling any firearm, make sure the firearm is unloaded!, remove magazine and bolt per the manuals instructions. 2. Remove the bolt anyway, as the bottom of the base will scrape the safety lever...line up the male dovetail (receiver) to the female dovetail (bottom of base) and slide forward. TIP: a little bit of lubrication along the male dovetail will allow a smoother fit and cause less damage to either of the finishes). 3. Line up the cut out with your ejection port. As a multi application base for the 452, 453 and 455, the older 452 and 453 had a longer port so on the 455 the base doesn't line up flush with both sides. But that's ok, you can either split the difference or line it flush with one side or the other. I prefer to move it forward as the taper of the dovetail on the rear of the receiver gives a gradual sloped up to the base look and lining it flush with one side of the port gives me immediate feedback if the base should ever come loose (like a witness mark). 4. Once aligned to your liking, start with a set screw to either side of the port / cut out. Make sure to use a little dab of Loctite or clear nail polish to ensure they don't come loose later. Just tighten enough to make contact with the receiver, then work your way to the other set screws. 5. Then when you are satisfied that the base is level and even, tighten down the set screw to D.I.P.'s recommended 6-8 ft lbs. I probably tightened mine down more, however you don't want to risk stripping them out. Total installation time was well under 10 minutes. The "Tacticool" crowd or traditionalists should find that the base does not take away from the overall look of the rifle: Keep in mind these are picatinny spec grooves, and there will be some play in the groove if using a weaver base. The trick is to bump one ring against one of the ridges in the base, then bump the other ring against another ridge - make sure they are opposing sides of the ridge (inside to inside or outside to outside) so that the rings are not allowed to move forward or backward, then tighten the rings to the base. The extended version that I ordered leaves enough gap to easily remove calibers in the 455, clearance is not an issue. The base isn't overly high profile. Using medium height rings and a 40mm objective lens optic, there was ample clearance, with even room to spare for a larger objective lens. In combination with the comb of the 455 stock (which is the same as the CZ 452 / 453 american or varmint platforms) the cheek weld was solid and comfortable - no need to add height from a cheek piece. This should also be carried over while using the base on the CZ Silhouette, Evolution, and Precision Trainer. The only place this may cause a cheek weld issue is on the LUX, Mannlicher-style stocks, the military trainer models, and perhaps the scout, due to the drops in their stock combs. All in all the D.I.P. bases offer several nice features, the ability to install it without needing special skills or a gunsmith, and compliments the rifle in both a "tactical" or traditional setup. As I'm utilitarian (AKA "cheap") Even the packaging the base came in could be used for storing other "Gun stuff", they could probably sell the empty packaging for just that reason. After 350 rounds, the base stayed solid. Other than it not lining up flush to the 455 ejection port (which is just knit picking), as it is also universal to the 452 / 453, I could find no fault with it.