Just received a set of the new ZKK600 Super QR mounts from eBay the other day... so a quick review for any ZKK fans out there. These mounts will also fit a CZ550, and they have recently listed them for the CZ550 Magnum and the 'ZKK600 Magnum'... I assume they mean the ZKK602

First impressions are of a very high quality set of mounts, fit and finish is right up there with EAW, Recknagel etc.
1", 30mm or 34mm alloy rings are offered. Windage adjustable at the rear ring.
No different ring heights available, but the standard ones fit a 50mm Ų OD objective housing with about 5mm clearance.
The mounts allow 3mm clearance between an un-altered ZKK bolt handle and a 43mm Ų ocular housing.

Quite lightweight at 190g (Magnum versions are 224g)... the main body, levers and clamps are CNC machined from alloy steel, skeletonised on the reverse side like an I-beam and nicely hot blued. A series of lightening holes have been machined down the bridge.
The front ring can be repositioned further back down the bridge in one of these holes to better clear the scope turret or to alter eye relief.
A cut out machined into the LHS of the mount exactly matches the ZKK's trademark receiver scallop, for a further weight save.

There is a windage adjustment screw neatly tucked away either side of the rear ring... tighten one and loosen the other to move the scope very precisely, no hint of any play. Very necessary on some early ZKK's with dovetails or barrel threads not parallel to the axis of the receiver. Otherwise you will soon run out of adjustment on the scope!
Very well designed indeed...

Look quite similar to the old Zeiss Jena QD ZF4/6 scope + mounts that were originally offered as an option with the Brno ZKK.
Couple of minor negatives were no box and no instructions... easy enough to work out but should have been included!
Three different sized Allen keys are included, along with two spare scope ring screws. Another nice touch.

Three main types of mount available, QR have the conventional projecting levers, Super QR with the curved cam lock fingers, and a simplified version semi-QR version that requires an Allen key. All feature a sturdy recoil lug that abuts the recess on the LHS of all ZKK receivers.

These mounts really can be removed and replaced in seconds without tools... not cheap, but comparable to EAW, Recknagel etc.
Will confirm whether they return to zero after a range trip, but with the high level of precision engineering evident there's no reason to think they would not.

Recommended if you want a set of high quality quick release CZ550/ZKK600 mounts with curved levers that can't snag clothing or pack straps.

BTW I have no connection to this eBay seller, this is just a heads-up for those fans out there who have also been frustrated for years about the lack of decent ZKK scope mounts