Standard Hole Spacing to fit popular holsters.
Care and maintenance: We recommend keeping your HLR Discreet Gear Clips™ lightly oiled to prevent corrosion and keep the black oxide finish looking it's best. All clips ship with a light to dry coating of oil on them. When you first receive them, give them a light wipe with a dry cloth to remove any residual oil. Hot black oxide while anti-reflective does not have very good corrosion inhibiting properties all by itself. What protects the metal is a topical coating of oil rubbed into the magnetite oxide layer. Basically the oxide acts like a sponge or carrier for the protectant and once it rubs off protection is minimal until a quick wipe of oil is applied.
Standard maintenance for black oxide is as follows. For normal every day use, put a couple drops of oil on the face of the clip and rub it in on all surfaces with a cloth once a month or so. Wipe it in until there is no residual left on the surface. That same cloth can be used over and over again and is more than sufficient once it soaks up a little bit of oil after the first few uses. The same procedure should be used on the nuts/bolts/screws/hardware you are using as well.