This four track digital recorder can record, line in and with its internal mics simultaneously. It offers three compulsory recording formats peak reduction, auto level and limiter all work great no complaints here. Great for video an sound engineering work and other professional applications. It has a built in speaker and records in 96, 48 and 44.1 khz formats and has a fantom power option for external xlr mics. Its takes three alkaline batteries and is supplied with a 2gb sd card this gives about 2 and a half hours recording time at the full sample rate. As seen in the photo the dr 40 has mic guards for usage protection. Completed files are downloaded to pc via usb 2 they also can be titled in the dr 40. This unit is portable easy to get to grips with packed with goodies and the recording quality is unsurpassed. Great bit of kit.