Pulsar PSP-B 56mm Adapter RingThe Pulsar PSP B 56mm Adapter Ring is an optional accessory which enables Krypton and Proton clip ons to be attached to optics whose objective diameter is 56 mm. Inserts with an inner diameter of 60 mm (for mounting the adapter on daytime optics with an outer lens diameter of 59. 7 60. 6 mm), 61 mm (60. 7 61. 6 mm), 62 mm (61. 7 62. 6 mm), 63 mm (62. 7 63. 6 mm), 64 mm (63. 7 64. 6 mm), 65 mm (64. 7 65. 6 mm) are provided as a standard accessory.