Overall Context: This appears to be a catalog excerpt, likely from Central Semiconductor, detailing various NPN and PNP transistors. It's aimed at engineers or technicians needing to select transistors for specific applications.

Key Information - Summary Table (organized by transistor model):

Transistor Model	Type (NPN/PNP)	Vce (Volts)	Ic (Amps)	Key Features/Notes
BSX19	NPN	40	20	General purpose
BSX20	NPN	40	20	General purpose
BSX21	NPN	120	90	General Purpose
BSX36	PNP	40	25	General Purpose
BSX49	NPN	500	250	General Purpose
BSX79	NPN	50	45	General purpose
BSY18	NPN	12	16	General purpose
BSY62	NPN	300	280	General Purpose
BSY79	NPN	120	200	General Purpose
BSY95A	NPN	20	15	General Purpose
BFX65	PNP	45	110	General purpose
BFY18	NPN	25	120	General Purpose
BFY74	NPN	45	60	General Purpose
BFY76	NPN	40	100	General Purpose
MM4257	PNP	6.0	500	Fast Switch
MM4258	PNP	12	700	Fast Switch

Important Notes & General Trends:

· Central Semiconductor: The document originates from Central Semiconductor, as seen in the footer `www.centralsemi.com`.
· NPN vs. PNP: The listing includes both NPN (Negative-Positive-Negative) and PNP (Positive-Negative-Positive) transistors.
· Fast Switch: The MM4257 and MM4258 are specifically designated as "Fast Switch" transistors, suggesting they are optimized for switching applications where speed is critical.
· Vce & Ic: `Vce` (Collector-Emitter Voltage) indicates the maximum voltage the transistor can handle between the collector and emitter. `Ic` (Collector Current) represents the maximum current the transistor can deliver.
· Datasheet Reference: This listing is a summary; for detailed specifications, application circuits, and safety information, you would need to refer to the full datasheet for each transistor model.