Reducer 1.25″ to 24.5mm.
With this reducer, you can use eyepieces with a 24.5 mm plug-in dimension
Use receptacles for 1.25″ accessories. This can get older, but
Use good eyepieces on newer telescopes instead of mothballing them
or for sale.
A filter thread allows the use of modern 1.25″ filters and
thus expands the possibilities enormously.
Outer plug dimension: 1.25″
Inside plug size 24.5mm
locking groove
Clamping by knurled screw