Easy- Snap Fit Diffuser. Clean and Sharp Profile Edge. Available in 1m or 2m LengthsExternal Cross Section: 20 x 20mm Internal Cross Section: 16 x 13mm Diffuser Visible Width: 20mm. Extruded aluminium channel profile for LED tape installation. Supplied with clip on half-square diffuser- end caps and clips for mounting onto walls or ceilings. Fully assembled- this profile has a box section to give a clean- sharp line with good light dispersion.. led strip profile-led strip fixing-led tape profile