King Gee Onyx 6CZ EH zip sided composite toe safety boot

King Gee builds the Onyx 6CZ around a composite toe rather than steel, which means the protection comes from a non-metal toe cap. King Gee calls that toe system K Shield. The upper is full grain water resistant leather, so it is meant to hold up to wet site conditions while keeping the look of a proper leather boot.

King Gee has also packed in a cluster of comfort and impact features. There is D3O lateral impact protection at the side of the foot, a FLEX TEC mechanism at the ankle so the boot moves with you, and a TriTec innersole for underfoot comfort. The outsole is the ShockGuard Pro system, rated by King Gee as 300 degree HRO with SRC slip and traction performance and an all terrain grip pattern.

The side zip suits anyone who wants to get in and out quickly without re-lacing every day. You can check the current listing on Done Right Safety for sizing and any standards confirmation before you order.

Deciding if a composite toe suits your site

A composite toe cap does the same protective job as steel but uses a non-metal material, so it does not conduct heat or cold the way steel does and it will not set off metal detectors. The trade off is that some sites or job specs still call for a specific toe type, so check your site's footwear requirement first. This boot pairs that K Shield composite toe with D3O at the side, which is aimed at lateral knocks rather than just the top of the foot.

Getting the fit right

Because this is a side zip boot, try it on with the zip done up the way you would actually wear it, then walk a few steps to feel the FLEX TEC ankle movement and where the TriTec innersole sits. Wear the socks you use on the job when you size it. Sizing and width details are listed on the product page, so confirm them there before you order rather than guessing from your usual shoe size.

Looking after the leather and outsole

Full grain leather lasts longer if you keep it clean and conditioned. Knock off mud before it dries, let the boots air rather than forcing them dry near a heater, and give the leather an occasional treatment to keep it water resistant. Keep an eye on the ShockGuard Pro outsole tread: once the grip pattern is worn smooth, traction drops, and that is the usual sign a replacement is due even if the upper still looks fine.

These are like-for-like alternatives: every product below is a composite toe work boot, so you are comparing genuine same-type options rather than adjacent styles. The first column is the King Gee Onyx 6CZ.

Pick the Onyx 6CZ if you want a leather, water resistant boot with a quick side zip and that extra D3O lateral protection and FLEX TEC ankle movement. The K28001 is the same Onyx platform, so choose between them on the variant details listed on each page rather than on the core build.

If listed certification is your deciding factor, the Hard Yakka X Range is the one here that states a standard (AS 2210.3:2019) on its facts, and it leans lighter and more sneaker-like. The Skechers goes for breathability with its leather and mesh upper and a TPU midsole. The King Gee boots do not list a standard in their facts, so confirm that on the product page if it matters for your site.

On the listing, the Onyx 6CZ reads as a well specified leather work boot. The combination that catches the eye is the composite K Shield toe with D3O lateral protection, the FLEX TEC ankle and the TriTec innersole, which together suggest King Gee has put real thought into both protection and all day comfort rather than just ticking the toe cap box. The water resistant full grain leather and the all terrain SRC outsole back up the claim that it is built for outdoor and variable conditions.

What is confirmed is the feature set above, drawn straight from the listing. What is not stated in the facts is a specific safety standard or an electrical hazard rating, despite the EH in the model name, and there are no sizing or width details in the facts here. Treat those as things to verify rather than assume.

Before you commit, check the product page or datasheet for the standard the boot is certified to, any EH rating, the available sizes and widths, and the colour. Those are the details that decide whether it suits your site's footwear policy and your foot.