A connection comprising: a first layer ; a second layer concentrically disposed about said first layer ; wherein said first and second layers are formed from corresponding first and second materials ; and wherein said first and second materials are selected from the group consisting of: a thermoplastic elastomer, polypropylene, polypropylene derivatives, polyethylene, polyethylene derivatives, polyolefin elastomer, polyvinylidene fluoride, polycarbonate, and acrylonitrile butadiene styrene; and a laser-induced seal between portions of said first and second layers ; wherein said laser-induced seal provides a fluid-tight engagement between said first and second layers , characterized in that concentric disposition of said second layer about said first layer positions a portion of a first layer external surface of said first layer adjacent to a portion of a second layer internal surface of said second layer ; wherein said laser-induced seal is distinguishable from a second layer external surface of said second layer ; wherein said laser-induced seal comprises at least one of: a recess which inwardly extends from said second layer external surface ; a protrusion which outwardly extends from said second layer external surface ; or a colored laser-induced seal which has a color that differs from the color of said second layer external surface ; and wherein said first layer is incorporated into a first conduit and said second layer is incorporated into a second conduit . a first layer ; a second layer concentrically disposed about said first layer ; wherein said first and second layers are formed from corresponding first and second materials ; and wherein said first and second materials are selected from the group consisting of: a thermoplastic elastomer, polypropylene, polypropylene derivatives, polyethylene, polyethylene derivatives, polyolefin elastomer, polyvinylidene fluoride, polycarbonate, and acrylonitrile butadiene styrene; and a laser-induced seal between portions of said first and second layers ; wherein said laser-induced seal provides a fluid-tight engagement between said first and second layers , characterized in that concentric disposition of said second layer about said first layer positions a portion of a first layer external surface of said first layer adjacent to a portion of a second layer internal surface of said second layer ; wherein said laser-induced seal is distinguishable from a second layer external surface of said second layer ; wherein said laser-induced seal comprises at least one of: a recess which inwardly extends from said second layer external surface ; a protrusion which outwardly extends from said second layer external surface ; or a colored laser-induced seal which has a color that differs from the color of said second layer external surface ; and a recess which inwardly extends from said second layer external surface ; a protrusion which outwardly extends from said second layer external surface ; or a colored laser-induced seal which has a color that differs from the color of said second layer external surface ; and wherein said first layer is incorporated into a first conduit and said second layer is incorporated into a second conduit . <EOS>