An NMR probe head (1) comprising one or more HF coils (2) arranged around a vertical axis of symmetry (z), and an HF network (3) surrounded by an apparatus (4) for shielding from external HF radiation comprising an electrically conductive shielding tube (5) arranged along a z-axis and that can be moved around the HF coils and the HF network in a z direction towards a base disc (6)A shielding disc (7) is provided at an axial distance from the base disc, wherein a tensible HF seal (8) is arranged between the shielding disc and the shielding tube. When the shielding tube is in a mounted state, the HF seal, in a first mounting state, can slide over the shielding disc in an unbraced and force-free manner. When the HF seal is in a second mounting state, the HF seal is mechanically braced between the shielding disc and the shielding tube to ensure an electrically conductive connection.