There is a free version and a paid version. The free version includes:

• Allows you to play and use instruments created in the full version.
• You cannot create your own samples.
• Ideal for loading kits created by others and using them in your projects.
• Includes a free demo kit with 8 instruments and a limited number of round robins. 
• MIDI Loop Support
• Fully MIDI-compatible
• Customizable mappings
• MIDI Loop Support (loops by Groove Monkee)

By KVRaudio: perfect-drums-by-naughty-seal-audio

Perfect Drums

• Allows you to create your own instruments using your own samples.
• Full access to all features, including the sampling engine, mixer, routing, and export.
• Includes the complete factory sound library. 
• Intelligent Sampling Engine: Users can create their own drum instruments from their own or imported samples. 
• Extensive Sound Library: Includes 131 meticulously recorded drum instruments from renowned manufacturers, including 13 bass drums, 12 snare drums, 29 toms, hi-hats, cymbals, and more. 
• Multi-microphone setup: Each instrument offers multiple sample groups such as Direct, FX, Overhead, Room, and Reverb, enabling flexible sound editing. 
• Flexible mixer: Featuring channel strips, buses, routing options, and effects such as the built-in FX Sample Group Parallel Processing for direct punch in the mix.
• Fully MIDI-compatible
• Customizable mappings: MIDI mappings can be customized and saved.
• MIDI Loop Support (loops by Groove Monkee)

Perfect Drums TCI

Perfect Drums TCI is a special version of Perfect Drums designed specifically for integration with the Slate Digital TRIGGER plugin. TCI stands for Trigger Control Interface.

• Includes 54 instruments from the factory library: 13 bass drums, 12 snare drums, and 29 toms (8 complete sets). 
• Each instrument features all sample groups: Direct, FX, Overhead, Room, Reverb. 
• It is not sold separately but is included with the purchase of the full version of Perfect Drums. 

With the TCI Pack, users of the Slate TRIGGER plugin can use real drum samples as replacement sounds when editing acoustic drums.