Renata CR1632 Lithium Coin Cell Watch Batteries - 20 Pack - Long-Lasting Power for Watches, Calculators, Key Fobs & Medical Devices

I used these in the Marshal transmitter on my falconry bird (a hawk). I've tried several brands of CR1632 and found the Renata's to last the longest. The Sony's don't last as long. The Eveready's are junk. The Battery Plus house brand CR1632s are way overpriced and only last as long as the Sony batteries.