SPDT relay: it has both normally open and normally closed terminals, terminal 87A is powered when the relay is inactive and switches the power to terminal 87 when the relay is activated
85 Coil, Ground
86 Coil, Trigger
30 Common connection to NO & NC terminals
87 Normally Open (N/O)
87a Normally Closed (N/C) - not present on 4 pin relays
Package Content: 4 x 12 V DC waterproof relay and harness

12-volt 5-prong relay.
12AWG Tinned Copper Wire: Pin 87a Yellow
12AWG Tinned Copper Wire: Pin 87 Blue
12AWG Tinned Copper Wire: Pin 30 Red
16AWG Tinned Copper Wire: Pin 85 Black
16AWG Tinned Copper Wire: Pin 86 White

Contact Material Copper
Contact Type Spdt
Current Rating 30 Amps, 40 Amps
Wattage 560.00
Nominal Coil Voltage: 12 V DC
Coil Power: 1.8 W
Coil Resistance: 80 Ω
Must Operate Voltage: 6~8 V DC
Must Release Voltage: 0.6~3.6 V DC
Maximum Applied Voltage: 15.6 V DC
Contact Ratings: NO 40A 14V DC
Contact Resistance: 100mMAX (at6VDC 1A)
Max Switching Current: 40A
Max Switching Power: 560 W

Life Expectancy Electrical: 100,000 Operations (at30 Operations/minute)
Life Expectancy Machanical: 10,000,000 Operations
Temperature Range: -30 ~ +80 degrees Celsius
Vibration Resistance: 10~55Hz, 1.5mm
Shock Resistance: Operations Extremes: 10g. Damage Limits: 100g
Hunidity: 40% ~ 85%
Insulation Resistance: 100mΩ Min at500VDC
Dielectric Strength Between Open Contacts: 500VAC (for one minute/sec)
Between Contactw and coil: 750AC (for one minute/sec)
Operate Tice: 7ms
Release Tice: 5ms

Tinned copper wiresTinned copper wires
Good electrical conductivity
Good corrosion resistance
Stronger oxidation resistance
5 terminals of the relay have been sealed for more stable performance. Good sealing feature & Excellent waterproof and dustproof performance Plug and play: Easy to install just make sure you follow the wiring diagram. Works for both positive and negative activation.

Note:
1, Excellent water-repellent and dustproof ability, but not using it in water 2, Be careful when inserting the relay into the socket. If you force it, you will bend the female connectors