Silverfoiltubes International Inc. - Micro Slim 5.5mm
NEW 25mm 1000 ROLLO RED FILTER ULTRA SLIM Tobbacco Cigarrette filter tubes | eBay
Someone was asking about this earlier. Here's a side by side picture of standard King Size tube with 20mm filter and a European Slim with a 20mm filter. The slims are 1mm
Source Cigarette filter Tubes Making Machine Slim on m.alibaba.com