Our Smooth Seal style have a special ridge under the buckle that are designed for use on a range of hard or softwall hoses, including thin walled layflat style hose and hardwall PVC hoses, as they ensure a 360° closure around the hose being clamped. Punch clamps are used in conjunction with any of our center punch tools/machine; they provide a secure, quick and easy installation method for on-site "non-critical application" repairs (NOT for use with steam, large bore air hoses, hazardous gases, or other critical applications - must be installed with a fully trained assembler).