Bulk is the package size of NTC thermistors. It's in the Bead, Glass package for convenience. To make NTC thermistors work, the resistance tolerance is ±10%. The temperature of NTC thermistors should be set to 300°C in order to ensure reliable performance.
GS303J1K Features
Package/Case: Bulk GS Series Operating Temperature: 300°C Mounting Type: Through Hole
GS303J1K Applications
There are a lot of Littelfuse Inc. GS303J1K NTC Thermistors applications.