End plug for a roll of material, roll of material and retention mechanism in a dispenser

An end plug for a roll of material to be inserted into a retention mechanism, comprising:

• a bearing member with dimensions to fit longitudinally into the retention mechanism,
• a receiving portion with dimensions to fit into a hollow core of the roll of material;
• wherein the bearing member comprises:
• a bearing pin comprising a counter surface facing the receiving portion;
• and
• a locking surface for locking the end plug in an end position in the retention mechanism, the locking surface and the counter surface being arranged to be inclined in opposite directions to constitute a potential well, the locking surface being arranged between the receiving portion and the bearing pin, the locking surface having at least one portion inclined with respect to the longitudinal axis of the bearing pin by an angle to the longitudinal axis of the bearing pin in the range of 117° to 141°, and the angle in combination with the counter surface produces a locking force of 15N to 19N.