HB523W.539 - Hawk DTC-30 brake pads; 
Hawk Dynamic Torque Control 30 (DTC-30) is a multi-purpose, torque modulating compound that is proven in a wide range of series. It offers superior release characteristics, a smooth pedal feel and initial grip for street circuits.
Operating temperatures: 37-650°C
Optimum temperature range: 37-425°C
The DTC-30 compound is often used on the rear axle of smaller racing vehicles. Drivers of MX-5 or S2000 Cups often choose these pads for the rear axle and combine them with a higher-friction compound on the front axle. These pads are also found on both axles of fast road vehicles when braking performance is the top priority and you are willing to accept a little extra noise and brake dust.

HB523D.539 - Hawk ER-1 Brake Pads;
The ER-1 compound was developed by Hawk Performance for the endurance racing market with one simple objective: to offer a higher coefficient of friction than competitive endurance pads, while maintaining equal or greater durability. Years of testing in America's most prestigious races have resulted in a complete compound that offers ideal modulation and communication with the pedal, with unprecedented friction stability across the entire temperature range. This consistency of performance, hour after hour, makes it ideal not only for endurance racing, but also for track day, time attack and even sprint races.
Operating temperatures: 200-870°C
Optimum temperature range: 370-590°C
 
HB523G.539 - Hawk DTC-60 brake pads; 
Hawk's DTC-60 racing compound offers extremely high deceleration and superior modulation and release characteristics. It is not an entry level race compound and should not be used on the street. It should be used when you are an experienced rider with track experience and have had problems with less aggressive compounds that overheated or did not provide enough bite.
Hawk DTC-60 racing brake pads have the same temperature range as Hawk's DTC-70, but produce less braking torque. Many drivers of smaller, lighter cars often use DTC-60 pads on the front and DTC-30 on the rear, while on larger, heavier, high-performance or racing cars, DTC-60 are more often used on the rear and DTC-70 on the front.
Operating temperatures: 205-870°C
Optimum temperature range: 370-595°C
 
Hawk Performance compounds may take up to 15 working days for delivery depending on availability