Blender is right. DC stuff is reportedly crapola. Most SKS shooter also report that any of the cover mounted scope mounts are not very stable and shift zero. If you are looking for a solid SKS scope mount there seems to be 2 decent ways to go:
Back in the 90's when I was writing for a popular gun magazine, I did an SKS article.
A bunch of the manufactures back then sent me their stuff including DC engineering. I got the same thing shown in your photo, thankfully for free. I really, truly, in every way if a piece of junk. I dug it out the other day and was wondering how someone in their right mind could sell something like this.
I appears to be cast steel. A very rough casting at that. It has to filled to be fitted, and then for it to hold 0, you have to tap it gently into the reciever. It is made to fit very, very tight. To remove it you also have to tap it out.
And my 2 cents............almost nothing they make aftermarket for the SKS is worth wasting money on.
That goes for:
Scopes & mounts (the rifle and cartridge were designed for body hits within 300 yards, but can do better in the right hands at somewhat longer range).
Hi-cap mags (nice thought, but you either give up reliability of feed or ease of reloading).
Stocks (they either add a lot of extra weight or are downright unwieldy when compared with the original issued wood).
Bipods (More extra weight and some are difficult to adjust under duress or on uneven surfaces).
I have some of all the above and rue the day I bought any of them. Some folks may like those "extras" but your best bet is to leave the rifle in original configuration so it will serve you the way it did its original masters. If you need a "Sniper-configured" rifle, a Hi-cap rifle, a "special forces" rifle, a squad support rifle or a "CQB" weapon, put your money into something that was built to do those things or is more suited to them when modified. They will cost more, but you get what you pay for.
Best of luck,
PS: I like the Techsights, but you still give up ease of rifle disassembly for cleaning or maintenance. That said, there's one on my Chikom and it's great for quick, accurate offhand shots.
Be 50 years old my eyes aren't quiet what they used to beat longer ranges 50 Yds and up I have no problems and iron sights work great but out to 100 and beyond I need the help of a scope. So I keep my Chinese original and my YUGO I did a Choate drill and tap mount,my local smith did the work for me for $25 I though that was a great deal to be honest,but he is a nice old gentleman that just love to tinker with guns and buy,sell and trade. I bought my NIB Chinese from him for $225 and I'm very proud of it anyways the Choate mount is rock solid about $30 mail order,I use a Bushnell Sportsview 3 x 9 x 32 on it and it shoots like a dream for me.
When I bought my yugo it came with something just like that. I never tried it out you can tell just by putting it on the gun and wiggling it that it would never hold zero. The best bet for a scope is to tap and drill. I just stuck with open sights cause the only good solution for a scope is to tap and drill and I didn't want to do anything that permanently altered the gun.
Or you could use the tapco stock that has a rail on the handguard and use a scope with lots of eye relief. I have the tapco t6 stock on mine and I really like it, and there 20 rnd mags are good, never had a problem with 4 of the ones I have. Just read up and the 10 items or less rules so you stay compliant with the 922 law. The thing I really like about it is I can switch it back to original form in less than ten minutes and you'd never know I had the t6 on it.