A device for the protection and covering of a watertight pipe lead-through, and adapted to be positioned around a pipe or a tube, comprising - a housing of a flexible material having a central opening, the housing having a cut-through portion, i.e. a cut entirely through the housing and extending from the outer bottom periphery of the housing and to the central opening whereby a gap between a first and a second portion of said housing can be or is formed, such that the housing can be applied to a pipe without having to disassemble the pipe installation; - and a locking mechanism for closing the gap and locking the housing in position around the pipe; characterized in that - the locking mechanism comprises first locking means provided on the first portion of the housing, and second locking means provided on the second portion of the housing, said locking means (20, 22) mating with each other, wherein - the first and second locking means (20, 22) are configured to be lockable to each other over a range of different positions along the circumference of said housing, wherein one of the first and second locking means is provided with teeth and the other of the first and second locking means is provided with mating recesses in which the teeth can engage, wherein the teeth are provided on said first portion of the housing, said first portion extending circumferentially, and wherein the teeth extend outwards in a radial direction, and wherein the recesses are provided on an inner wall of the housing, or wherein the teeth are provided on the inner wall of the housing, and wherein the teeth extend inwards in a radial direction, and wherein the recesses are provided on said first portion of the housing, said first portion extending circumferentially. - a housing of a flexible material having a central opening, the housing having a cut-through portion, i.e. a cut entirely through the housing and extending from the outer bottom periphery of the housing and to the central opening whereby a gap between a first and a second portion of said housing can be or is formed, such that the housing can be applied to a pipe without having to disassemble the pipe installation; - and a locking mechanism for closing the gap and locking the housing in position around the pipe; characterized in that - the locking mechanism comprises first locking means provided on the first portion of the housing, and second locking means provided on the second portion of the housing, said locking means (20, 22) mating with each other, wherein - the first and second locking means (20, 22) are configured to be lockable to each other over a range of different positions along the circumference of said housing, wherein one of the first and second locking means is provided with teeth and the other of the first and second locking means is provided with mating recesses in which the teeth can engage, wherein the teeth are provided on said first portion of the housing, said first portion extending circumferentially, and wherein the teeth extend outwards in a radial direction, and wherein the recesses are provided on an inner wall of the housing, or wherein the teeth are provided on the inner wall of the housing, and wherein the teeth extend inwards in a radial direction, and wherein the recesses are provided on said first portion of the housing, said first portion extending circumferentially. wherein one of the first and second locking means is provided with teeth and the other of the first and second locking means is provided with mating recesses in which the teeth can engage, wherein the teeth are provided on said first portion of the housing, said first portion extending circumferentially, and wherein the teeth extend outwards in a radial direction, and wherein the recesses are provided on an inner wall of the housing, or wherein the teeth are provided on the inner wall of the housing, and wherein the teeth extend inwards in a radial direction, and wherein the recesses are provided on said first portion of the housing, said first portion extending circumferentially.