The new 5-LINE Molded Front and Back Plugs are better in a number of ways. The most noticeable difference is in the very unique new design featuring the LANSAS proprietary “Flat-Rib” design which holds 60% more back pressure than standard O-ring ribbed plugs. We are using our improved reformulated rubber and laying the fabric in a way that the plugs can get the widest range of use on the market today. As with all other LANSAS products included in the 5-LINE group, our 5-LINE Multi-Size Front and Back plugs are equipped with the LANSAS RP2 – Rupture Protection. We trust in this design enough to back it with the 5-LINE 5 YEAR WARRANTY. If you are looking for the most ROI look no further than the LANSAS 5-LINE where once again we show LANSAS is BETTER BY DESIGN since 1955.