Endoscopic apparatus, comprising: a probe comprising an anterior component and a posterior component; and a flexible dual-sleeved tube, comprising a flexible external sleeve and a flexible internal sleeve within the external sleeve, coupled between the anterior component and the posterior component so as to define an enclosure between the sleeves, which enclosure is inflated in order to propel the anterior component within a lumen, characterized by comprising at least one tube fixedly connected to the anterior component and residing within the internal sleeve, wherein the anterior component comprises one or more openings, to which the at least one tube is fixedly attached, wherein the anterior component comprises an anterior-component chamber, and wherein the external sleeve comprises an anterior-component portion which is held in a compact state within the anterior-component chamber and which feeds out from a proximal end of the anterior component as the anterior component is propelled within the lumen, wherein the external sleeve feeding out from for the anterior component chamber remains fixed in a longitudinal direction of the endoscopic apparatus, when the enclosure is inflated, wherein the internal sleeve comprises a posterior-component portion which is held in a compact state coupled to the posterior component and which feeds out from a distal end of the posterior component as the anterior component is propelled within the lumen, wherein the internal sleeve feeding out from the distal end of the posterior component moves at the same rate as the anterior component so that there is no relative motion between the one or more tubes and the internal sleeve when the enclosure is inflated. a probe comprising an anterior component and a posterior component; and a flexible dual-sleeved tube, comprising a flexible external sleeve and a flexible internal sleeve within the external sleeve, coupled between the anterior component and the posterior component so as to define an enclosure between the sleeves, which enclosure is inflated in order to propel the anterior component within a lumen, characterized by comprising at least one tube fixedly connected to the anterior component and residing within the internal sleeve, wherein the anterior component comprises one or more openings, to which the at least one tube is fixedly attached, wherein the anterior component comprises an anterior-component chamber, and wherein the external sleeve comprises an anterior-component portion which is held in a compact state within the anterior-component chamber and which feeds out from a proximal end of the anterior component as the anterior component is propelled within the lumen, wherein the external sleeve feeding out from for the anterior component chamber remains fixed in a longitudinal direction of the endoscopic apparatus, when the enclosure is inflated, wherein the internal sleeve comprises a posterior-component portion which is held in a compact state coupled to the posterior component and which feeds out from a distal end of the posterior component as the anterior component is propelled within the lumen, wherein the internal sleeve feeding out from the distal end of the posterior component moves at the same rate as the anterior component so that there is no relative motion between the one or more tubes and the internal sleeve when the enclosure is inflated.