Agena offers what is arguably the largest selection of after-market end caps and dust plugs in the astronomy industry. Available in dozens of sizes and in a choice of materials and colors, we just might have that hard-to-find end cap to replace the one you lost (or never had) for your eyepieces, binoculars, accessories, etc.
Black plastic cap. Sold individually.
Please note that the inside of this end cap has an imprint of "51.5." This refers to the dimension (D) of the cap (see definitions below) and not dimension (A) which is the usable inner diameter of the end cap and is a bit smaller than the marked size.
A = 50.2mm / 1.98"
B = 53.9mm / 2.12"
C = 10.2mm / 0.4"
D = 51.1mm / 2.01"
Internal Ridges = Yes
Imprint on inside of cap states "51.5"
(1) Some, but not all, end caps have 6-8 ridges on the inside rim. If these are present, the end cap size (A) is measured between diametrically opposite ridges as this will be the smallest internal dimension.
(2) If no ridges are present, (D) will be the same as (A). If ridges are present, (D) is typically 0.5-1mm larger than (A).
(3) The inside depth of the end cap is typically 1-2mm smaller than dimension (C).
(4) Dimensions (B) and (C) are subject to change without notice.