Breaker panel comprising: - a removable front cover comprising apertures; and - a plurality of circuit breakers, each circuit breaker comprising, at one end, a foot, and at the opposite end, a head received into the interior of a respective aperture of the front cover, this head comprising: • a frustoconical portion that flares in the direction of the foot, from a top to its base; and • a shoulder, perpendicular to a plug-in direction, located level with the base of the frustoconical portion, - the frustoconical portion comprising in immediate succession when traced from its base to its top: • a frustroconical seal made of an elastomer, this frustroconical seal having a first frustroconical face, exposed directly to the exterior and extending from a lower edge to an upper edge; and • a conic frustum made of a material that is harder than the material of the frustroconical seal, this conic frustum having a second frustroconical face, directly exposed to the exterior and extending from a lower edge to an upper edge contained in the top of the frustroconical portion; characterized in that: - the distance, in the plug-in direction, between the upper edge of the first frustroconical face and the shoulder is at least two times smaller than the distance, in the plug-in direction, between the upper and lower edges (47A, 47B) of the second frustroconical face; and - the upper edge of the first frustroconical face is set back, towards the interior of the circuit breaker, relative to the lower edge of the second frustroconical face. - a removable front cover comprising apertures; and - a plurality of circuit breakers, each circuit breaker comprising, at one end, a foot, and at the opposite end, a head received into the interior of a respective aperture of the front cover, this head comprising: • a frustoconical portion that flares in the direction of the foot, from a top to its base; and • a shoulder, perpendicular to a plug-in direction, located level with the base of the frustoconical portion, • a frustoconical portion that flares in the direction of the foot, from a top to its base; and • a shoulder, perpendicular to a plug-in direction, located level with the base of the frustoconical portion, - the frustoconical portion comprising in immediate succession when traced from its base to its top: • a frustroconical seal made of an elastomer, this frustroconical seal having a first frustroconical face, exposed directly to the exterior and extending from a lower edge to an upper edge; and • a conic frustum made of a material that is harder than the material of the frustroconical seal, this conic frustum having a second frustroconical face, directly exposed to the exterior and extending from a lower edge to an upper edge contained in the top of the frustroconical portion; • a frustroconical seal made of an elastomer, this frustroconical seal having a first frustroconical face, exposed directly to the exterior and extending from a lower edge to an upper edge; and • a conic frustum made of a material that is harder than the material of the frustroconical seal, this conic frustum having a second frustroconical face, directly exposed to the exterior and extending from a lower edge to an upper edge contained in the top of the frustroconical portion; - the distance, in the plug-in direction, between the upper edge of the first frustroconical face and the shoulder is at least two times smaller than the distance, in the plug-in direction, between the upper and lower edges (47A, 47B) of the second frustroconical face; and - the upper edge of the first frustroconical face is set back, towards the interior of the circuit breaker, relative to the lower edge of the second frustroconical face.