300 to 450mm, and we see most orders for 400mm since it fits standdard depth keyboard trays—pricing runs about $2.50 per set for samples, $1.80 in the mid-range of 500 units, and our company can get under $1.20 when you're pushing 5,000 or more, and that's where the real value is.

We've had these on workstations handling CAD keyboards and drafting table drawers that get opened 40 times a day—the 15kg load capacty is overkill here but it keeps the motion steady; what it does is outlast cheap shelving slides by a few years, honestly.

Teh 1.2mm cold rolled steel is work hardened so you don't get that flex problem in longer spans, and the zinc or black finish holds up fine unless you're in a salt spray enviroment (check our TDS for that), but for office furniture or home workshop cabinets it's pretty much bulletproof.
You'll want to confirm your instalation gap is 9.8mm give or take 0.2 since curved balls run tight—some e-commerce sellers with generic 27mm slides leave that spec off and then you're shimming with washers, which we've seen frequently.

Actually, most buyers go with black for the keyboard drawer application because it hides finger oils better than zinc, though the zinc option is easier to wipe clean for labs; we usually have both finishes in stock for the common lengths but lead time is about 10 working days or so if we need to roll special sizes.
It's rated for 15kg per pair, so it can handle a typical heavy-duty keyboard drawer with a full-size mechanical keyboard plus some accessories without issues.
Yes, the required installation gap is 9.8mm ±0.2mm. If your gap is tighter or wider, the balls may bind or the rail may rattle, so measure carefully before mounting.
Both finishes are available – zinc plated for a standard look or black for a more hidden, sleek appearance. Just specify which one you need when ordering.
Our MOQ is typically 100 pairs per length and finish combination, but for smaller trial orders we can sometimes accommodate 50 pairs. Check with your sales contact.
Yes, we can include ISO 9001 certification copies with your order upon request. Just let us know before shipping and we'll attach them to the packing list.