If you’re looking for a grab‑and‑go shim solution that keeps jobs moving, this tub of 400 Unifix Assorted Flat Packers is the one you’ll reach for first. Each rigid, colour‑coded packer makes it easy to dial in the exact height you need—whether you’re levelling base units, setting windowsills, or squaring up door and window frames. The 28×100mm footprint sits neatly under frames and fixtures, giving you stable, repeatable results without fuss.

Because the thicknesses range from 1–6mm, you can shim precisely or stack responsibly to bridge uneven surfaces. The sealed tub is site‑friendly—tip out what you need, snap the lid back on, and keep the rest clean and organised. It’s a simple way to reduce install time, avoid callbacks, and keep your finish consistent across the whole job.

Prefer to stock up on specific sizes or larger quantities? Browse all flat packers in our construction sundries to mix and match what you use the most. And if you’re standardising across the site, you can explore our wider fixings range for anchors, fasteners, and more to keep your kit consistent end‑to‑end. Want a bit of background on why trades trust Unifix? Here’s a quick read on the brand’s heritage and quality credentials—trusted by merchants, distributors, and tradespeople for decades.