Plug-Type Brass Resistance Box, Model B Geology_Geology Charts & Models the f/3 curvature stretching the

the f/3 curvature stretching the focal throw for demos that need the focal point set comfortably beyond the mirror face

with banana-plug terminals for optical-bench and physics-demonstration circuit setups

25-inch frame with draining pins for post-wash inversion and drying

sized for very-high-turn-count coil construction and microcurrent prototyping work

Three 1W resistors of different values on a single base with six 4mm terminals

Plug-Type Brass Resistance Box, Model B Geology_Geology Charts & Models the f/3 curvature stretching thePlug type resistance box with constantan wire coils between split brass contact blocks, providing low temperature coefficient reference values for Ohm's law and bridge calibration work.