You used this one?Link to The Metal House website. I used the smallest size 6mm x 3mm.
Rubber U-Channel Trims from - The Metal House
Made in the UK from top quality EPDM, our Rubber U-Channel Trims are ideal for creating flexible panel edging or seals. Cut to length with fast delivery!themetalhouse.co.uk
Small Rubber U Channel 6mm x 3mm from The Metal House
Small Rubber U Channel 6mm x 3mm to fit 0.5-1.5mm wide material. Rubber extrusion suitable for a wide range of applications. Rapid UK delivery
themetalhouse.co.uk