US$ 12.99
Optically-worked glass double convex lens with a 150mm focal length and 1
Zinc-plated rectangular steel bar-magnet pair packaged with keepers that bridge the poles in storage
5% accuracy
and psychology teaching
packaged with carbons
1Ω Resistance Unit Base_Octagonal Optically-worked glass double convex lensOne ohm metal film resistance unit at plus or minus 1% accuracy with a 0. 7V maximum rating, providing the lowest value reference in the line for low resistance Ohm's law and bridge work.