ZJK Open C-Frame Optical Adjustment Mounts

The ZJK family holds round optics in an open, half-surround cradle and offers both left- and right-hand layouts with two-axis or three-axis adjustment. Its 32 online SKUs form four eight-size groups. Every dedicated model image labels optic size and optic-center height, allowing the mounting geometry to be recorded without guessing from model codes. Sizes cover 0.5, 1, 1.5, 2 and 3 inches plus 15, 20 and 30 mm. Center height is a mechanical reference, not optic diameter or clear aperture. Family images show black-anodized aluminum-alloy construction, an M4 nylon-tip optic-retaining screw, fine adjustment screws and post-mounting features. The half-inch images label an unusual 12.79 mm center height; that source value is retained and flagged for confirmation. English artwork is a selection visual, not a model-level engineering drawing.

Thirty-two combinations and handedness

The four sets are left-hand/two-axis, left-hand/three-axis, right-hand/two-axis and right-hand/three-axis, each with eight optic-size choices. Dedicated R-model photographs explicitly say right-hand; corresponding non-R images say left-hand. Each image also states the adjustment format. Choose the knob side to suit neighboring equipment rather than assuming a mount can be flipped without changing geometry.

Optic seat and center height

Model images label compatible optics as 0.5 in, 15 mm, 1 in, 1.5 in, 2 in, 20 mm, 30 mm or 3 in. They separately label optic-center heights of 12.79, 25.4, 35.1 or 50.8 mm; several optic sizes share a height. The 12.79 mm half-inch figure is copied from the artwork and needs manufacturer confirmation. Center height is neither optic diameter nor usable clear aperture. Optic thickness, edge profile and clamping range are unstated.

Fine adjustment, retention and mounting

A family diagram identifies an M4 nylon-tip set screw for optic retention. It references M4×0.25 fine adjustment for the half-inch compact example and M6×0.25 for other pitch/tilt examples. It also shows an M4 threaded hole or M4 countersunk feature with an M6 threaded hole for post installation. Verify exact screw and hole details for the selected model; the demonstration post is not assumed included.

Engineering limits not documented

No numerical angular travel, resolution, backlash, load, retention force, clear aperture, overall depth or tolerance is provided. Three-axis images show the extra adjustment knob without axis-by-axis travel data. Before ordering, check optic outside diameter and thickness, center height, adjacent clearance and the actual packing list.

Selection checklist

Choose optic size, handedness and two/three-axis format

Check each center height and verify the 12.79 mm label

Confirm optic thickness, retention and clear aperture

Verify post fit, adjustment travel and included parts

To be confirmed

Whether the 12.79 mm half-inch center height is a label error

Optic thickness range, retention force and clear aperture

Per-model adjuster details, travel, backlash and load

Overall depth, tolerances, material grade and supplied quantity