Reed Relay Demonstration Board Subcategory_Entomology Supplies 12 VDC converter for accessory

12 VDC converter for accessory battery

Hand-painted arterial red and venous blue vessels trace the full systemic and pulmonary circulation across a mounted human figure for cardiovascular teaching

sized as bulb-spares for three-cell battery packs and ray-box optics work in physics labs

Greatly magnified transverse dicot stem model on a mounted base exposes vascular bundle arrangement and primary tissue layers for advanced botany teaching

Reed Relay Demonstration Board Subcategory_Entomology Supplies 12 VDC converter for accessoryDemonstrates electromagnetic switching on a base with 4mm plug connections, where current through a coil closes a separate contact and shows how a small signal controls a larger circuit.