Coin Cell Battery - 20mm (CR2032) - PRT-00338 - SparkFun Electronics

Energizer 2032 Batteries (2 Pack), 3V Lithium Coin Batteries

Coin Cell Battery Holder - 2xCR2032 (Enclosed) - PRT-12618 - SparkFun Electronics

Coin Cell Battery - 20mm (CR2032) - PRT-00338 - SparkFun Electronics

Coin Cell Battery - 20mm (CR2025) - PRT-11928 - SparkFun Electronics

Basics CR2032 3 Volt Lithium Coin Cell Battery - 4 Pack

BU2032SM-BT-GTR MPD (Memory Protection Devices), Battery Products

Coin Cell Battery Holder - 20mm (SMD) - PRT-11892 - SparkFun Electronics

Coin Cell Battery Holder - 20mm (Sewable) - DEV-08822 - SparkFun Electronics

Coin Cell Battery Holder - 20mm (PTH) - DEV-12641 - SparkFun Electronics

SparkFun Simon Says - Through-Hole Soldering Kit from MindKits New Zealand

Key Fob Enclosure with Button Pad - PRT-09377 - SparkFun Electronics